PURPOSE: To provide a vulcanization accelerator for chloroprene synthetic rubber having stable resistance to scorching, a high vulcanizing speed, and capable of giving vulcanized rubber with excellent physical properties, contg. a polyhydroxydiphenyl disulfide as an effective ingredient.

CONSTITUTION: The titled vulcanization accelerator is formed by incorporating a polyhydroxydiphenyl disulfide (e.g., 2,2',3,3'-tetrahydroxydiphenyl disulfide) as an effective ingredient. The vulcanization accelerator is blended with a chloroprene synthetic rubber by means of a mixer such as a Bandury mixer or open roll mill, in an amt. of 0.3W5pts.wt., pref. 0.5W3pts.wt., based on 100pts.wt. rubber.