The present curable composition comprises an organosilicon compound produced by hydrolysis copolycondensation of (A) a silicon compound R0Si(R1)nX13-n [wherein R0 represents a (meth)acryloyl group; and X1 represents a hydrolyzable group] and (B) a silicon compound SiY14 [wherein Y1 represents a siloxane-bond forming group] under an alkaline condition at a ratio of compound (A) to compound (B) of 1:(0.3 to 1.8) by mol. The present process for producing an organosilicon compound comprises a reaction process of conducting alcohol exchange reaction of a silicon compound. SiY24 [wherein Y2 represents a siloxane-bond forming group] in 1-propanol to produce a composition; and a condensation process of adding a silicon compound R0Si(R1)nX23-n [wherein R0 represents a (meth)acryloyl group; and X2 represents a hydrolyzable group] to the composition to perform the hydrolysis copolycondensation of the silicon compounds under alkaline conditions.