PURPOSE: To obtain a curable compsn. having an excellent curing speed by compounding (meth)acrylic acid ester, a peroxy compd, a specific anaerobic accelerator and dithiol acid salt.

CONSTITUTION: A curable compsn. consists of at least one (meth)acrylic acid ester (e.g.; diethylene glycol dimethacrylate, etc.), (A), a peroxy compd. (e.g.; benzoylperoxide, etc.), (B) of which the amt. is effective to start polymn., a usual amt. of an anaerobic accelerator compd. (e.g.; benzoic acid suflimide, etc.), represented formula I (C) and a dithiol acid salt represented by formula II [wherein Z is R2NC, R1SC or (OR1)2P; M is an n-valent transition metal selected from Cu, Co, Ni, Mo, Mn, Cr, Ru, Fe and V; n is 1, 2 or 3; R is a hydrocarbon or hydroxyhydrocarbon and R1 is a hydrocarbon group substd. by OH or a halo group or interrupted by an ether oxygen atom] (D) in an amt. effective to accelerate polymn.