There are provided a photocurable composition capable of being readily cured by irradiation of ultraviolet rays and a cured product of the photocurable composition, as well as a coating composition and a coating film obtained from the coating composition. The cured product exhibits a high refractive index, a less discoloration and an excellent transparency. The present invention relates to a photocurable composition comprising (A) an episulfide compound containing a thiirane ring; and (B) a photo-base generator represented by the general formula (1): ##STR00001## wherein Ar is phenyl, etc.; R is an alkyl group, etc.; --A.sup.+ is an ammonium ion; and X.sup.- is a borate anion, etc., and a coating composition comprising the photocurable composition and (C) a modified silicone oil, as well as a cured product and a coating film obtained from these compositions.