PURPOSE: To increase the polymerization and curing rate of a coldpolymerizable resin for dental use containing a pyrimidinetrione derivative as a polymerization initiator and an organic metal compound and an organic halogen compound as accelerators without deteriorating the transparency, color stability and physical properties of the resin.

CONSTITUTION: The polymerization and curing rate of a dental resin can be increased without deteriorating the above-mentioned advantages of cured product by polymerizing (A) a polymerizable compound having one or more ethylenic unsaturated double bonds, e.g. mono or polyfunctional methacrylate or acrylate in the presence of (B) 1-cyclohexyl-5-ethylpyrimidinetrione, (C) one or more organic metal compounds selected from acetylacetone copper, 4-hexylbutyric acid copper salt, cupric acetate, acetylacetone manganese, manganese naphthenate, etc., (D) an organic halogen compound and (E) a morpholine derivative. The amounts of the components B to E are preferably 0.01-10 pts.wt., 0.001-0.2 pts.wt., 0.1-5 pts.wt. and 0.1-15 pts.wt. based on 100 pts.wt. of the component A, respectively.