To provide a sealing resin composition for an optical element which exhibits high transparency, excellent resistance to an ultraviolet ray and high refractive index, in combination.

This sealing resin composition for the optical element comprises (i) a ladder or random structure of a silsesquioxane derivative and (ii) an inorganic fine particle as a main component, and is in the state of the B-stage. The silsesquioxane derivative is obtained by co-hydrolyzing and co-condensating a trialkoxysilane (A) having a 1-20C alkyl group or a phenyl group which may have a 1-8C hydrocarbon group, and a trialkoxysilane (B) having a substituent containing a reactive cyclic ether group.