the present invention relates to a chemical and pharmaceutical technology , and in particular to a stat3 and erk signal pathway inhibitor and a use thereof . the present invention provides a stat3 and erk signal pathway inhibitor . the inhibitor mainly consists of a mogroside and / or an analog thereof . the mogroside and the analog thereof inhibit the phosphorylation of a transcription factor stat3 and the phosphorylation of an erk . the method for preparing the mogroside and the analog has the characteristics of simpleness , strong operability and high purity of products . the present invention furtherprovides a use of the stat3 and erk signal pathway inhibitor in the preparation of drugs for treating tumors , which realizes the purposes of inhibiting the proliferation of cancer cells and promoting the apoptosis of cancer cells and has a very good inhibition effect on cancers .