Mr. Justice Rehnquist
delivered the opinion of the Court.
Petitioner Splawn was convicted in 1971 of the sale of two reels of obscene film, a misdemeanor violation of California Penal Code §311.2 (West 1970). After the conviction was affirmed on appeal by the California First District Court of Appeal and the State Supreme Court denied review, this Court granted certiorari, vacated the judgment, and remanded for consideration in light of our decision in Miller v. California, 413 U. S. 15 (1973), which had set forth the standards by which the constitutionality of § 311.2 was to be determined. After the State Supreme Court ruled that the statute satisfied the requirements articulated in Miller, see Bloom v. Municipal Court, 16 Cal. 3d 71, 545 P. 2d 229 (1976), the Court of Appeal again affirmed the conviction and the California Supreme Court denied petitioner’s motion for a hearing.
We again granted certiorari, 429 U. S. 997 (1976), to consider petitioner’s assorted contentions that his conviction must be reversed because portions of the instructions given to the jury during his trial render his conviction violative of the First and Fourteenth Amendments. He claims that the instruction allowed the jury to convict him even though it might otherwise have found the material in question to have been protected under the Miller standards. He also contends that the same portions of the instructions render his conviction invalid by reason of the constitutional prohibition against ex post facto laws and the requirement of fair warning in the construction of a criminal statute enunciated in Bouie v. City of Columbia, 378 U. S. 347 (1964). We consider these contentions in light of the fact that petitioner has abandoned any claim that the material for the selling of which he was convicted could not be found to be obscene consistently with the First and Fourteenth Amendments, and any claim that the California statute under which he was convicted does not satisfy the requirements articulated in Miller, supra.
As it was understood by the California Court of Appeal, petitioner’s challenge is leveled against the following portion of the instructions:
“In determining the question of whether the allegedly obscene matter is utterly without redeeming social importance, you may consider the circumstances of sale and distribution, and particularly whether such circumstances indicate that the matter was being commercially exploited by the defendants for the sake of its prurient appeal. Such evidence is probative with respect to the nature of the matter and can justify the conclusion that the matter is utterly without redeeming social importance. The weight, if any, such evidence is entitled [to] is a matter for you, the Jury, to determine.
“Circumstances of production and dissemination are relevant to determining whether social importance claimed for material was in the circumstances pretense or reality. If you conclude that the purveyor’s sole emphasis is in the sexually provocative aspect of the publication, that fact can justify the conclusion that the matter is utterly without redeeming social importance.” App. 38-39.
There is no doubt that as a matter of First Amendment obscenity law, evidence of pandering to prurient interests in the creation, promotion, or dissemination of material is relevant in determining whether the material is obscene. Hamling v. United States, 418 U. S. 87, 130 (1974); Ginzburg v. United States, 383 U. S. 463, 470 (1966). This is so partly because, as the Court has pointed out before, the fact that the accused made such an appeal has a bearing on the ultimate constitutional tests for obscenity:
“The deliberate representation of petitioners’ publications as erotically arousing, -for example, stimulated the reader to accept them as prurient; he looks for titillation, not for saving intellectual content. Similarly, such representation would tend to force public confrontation with the potentially offensive aspects of the work; the brazenness of such an appeal heightens the offensiveness of the publications to those who are offended by such material. And the circumstances of presentation and dissemination of material are equally relevant to determining whether social importance claimed for material in the courtroom was, in the circumstances, pretense or reality — whether it was the basis upon which it was traded in the marketplace or a spurious claim for litigation purposes.” Ibid.
Petitioner’s interpretation of the challenged portions of the instructions in his case is that they permitted the jury to consider motives of commercial exploitation on the part of persons in the chain of distribution of the material other than himself. We upheld a similar instruction in Hamling, supra, however, wherein the jury was told that it could consider “whether the materials had been pandered, by looking to their '[m]anner of distribution, circumstances of production, sale, . . . advertising . . . [, and] editorial intent . . . .’ This instruction was given with respect to both the Illustrated Report and the brochure which advertised it, both of which were at issue in the trial.” 418 U. S., at 130.
Both Hamling and Ginzburg were prosecutions under federal obscenity statutes in federal courts, where our authority to review jury instructions is a good deal broader than is our power to upset state-court convictions by reason of instructions given during the course of a trial. See Cupp v. Naughten, 414 U. S. 141 (1973); Henderson v. Kibbe, ante, p. 145. We can exercise the latter authority only if the instruction renders the subsequent conviction violative of the United States Constitution. Questions of what categories of evidence may be admissible and probative are otherwise for the courts of the States to decide. We think Hamling, supra, and Ginzburg, supra, rather clearly show that the instruction in question abridges no rights of petitioner under the First Amendment as made applicable to the States by the Fourteenth Amendment.
But petitioner contends that even though this be so, the particular portions of the instructions of which he complains were given pursuant to a statute enacted after the conduct for which he was prosecuted. In his view, therefore, his conviction both violates the constitutional prohibition against ex post facto laws, see Calder v. Bull, 3 Dall. 386, 390 (1798), and failed to give him constitutionally fair warning of the prohibited conduct with which he was charged. Bouie v. Columbia, supra. We find these contentions to be without merit, and we reject them.
The section of the California Penal Code defining the substantive misdemeanor with which petitioner was convicted, § 311.2, was in full force and effect at all times relevant to petitioner’s conduct. California Penal Code § 311 (a) (West 1970), which authorized the above-quoted instructions, was enacted after part of the conduct for which he was convicted but prior to his trial. That section, however, does not create any new substantive offense, but merely declares what type of evidence may be received and considered in deciding whether the matter in question was “utterly without redeeming social importance.”
Petitioner’s ex post facto argument is based on his reading of an earlier decision of the Supreme Court of California, People v. Noroff, 67 Cal. 2d 791, 433 P. 2d 479 (1967). His view is that under that case evidence such as was admitted here would not have been admissible at his trial on the substantive offense but for the enactment of §311 (a)(2). He claims that such a change in procedural rules governing his trial amounts to the enactment of an ex post facto law in violation of Art. I, § 9, cl. 3. The California Court of Appeal’s opinion in this case rejected that contention, and since it is a contention which must in the last analysis turn on a proper reading of the California decisions, such a determination by the California Court of Appeal is entitled to great weight in evaluating petitioner’s constitutional contentions.
The Court of Appeal, commenting on Noroff, said with respect to the California Supreme Court’s decision in that case:
“The court did not, however, disapprove of any use of evidence of pandering for its probative value on the issue of whether the material was obscene. It merely rejected the concept of pandering of nonobscene material as a separate crime under the existing laws of California.” App. to Pet. for Cert. ix.
We accept this conclusion of the California Court of Appeal, and therefore find it unnecessary to determine whether if § 311 (a) (2) had permitted the introduction of evidence which would have been previously excluded under California law, petitioner would have had a tenable claim under the Ex Post Facto Clause of the United States Constitution.
Bouie v. City of Columbia, supra, holds that the elements of a statutory offense may not be so changed by judicial interpretation as to deny to accused defendants fair warning of the crime prohibited. No such change in the interpretation of the elements of the substantive offense prohibited by California law took place here, and petitioner may therefore derive no benefit from Bouie.
We thus find no merit in petitioner’s claims based on First and Fourteenth Amendment protection of nonobscene matter, the constitutional prohibition against ex post facto laws, or Bouie v. City of Columbia. We have considered petitioner’s other claims, which appear to be variations on the same theme, and likewise reject them. The judgment of the California Court of Appeal is
Affirmed.