benzophenone derivatives expressed by the following general expression : a . sub . n wherein a in the above general expression is a residual group obtained by removing one hydroxyl group from sugar or sugar alcohol , and b is a benzophenone group shown by the following general expression ## str1 ## wherein r 1 through r 10 each is expressed by hydrogen , hydroxyl group , an alkoxy group , or the aforesaid binder c , and at least one of them is the binder c . in the case of an alkoxy group , preferably the number of carbon atoms is 1 to 4 . c is equivalent to -- o -- r -- , or 1 mole of glycerin with one hydroxyl group therein bound to a and another hydroxyl group to b . the benzophenone derivatives according to the present invention have excellent capability to absorb ultraviolet rays as well as high compatibility with polar solvent . also the external preparation for skin in which the benzophenone derivatives are mixed can be mixed in a polar base with wide availability for industrial purpose .