Effect of day length(DL) and supplementary 1ight luminosity(SLL) on bolting and florescence of Brassica Canpestras L. was studied with supplementary 1ight treatment at night after seed or seedling vemalization. The result indicated that supplementary light treatment was more effecitive than the check; The bud appearance, bolting and f1orecence of Chinese cabbage(B.camtpestris L. ssp. pekanensis)cane out earlier with SLL increasing during 0-290 μmol/(m²·s), and also were improved by proper plant growth through supplementary light; When DL surpass 16 h, the bolting and f1orescence of Chinese cabbage, Paktroi(B.camtpestris L. ssp. chinensis) and turnip(B.camtpestris L. ssp. rapifera)、were accelerated. And this effect reached summit in the 24 h treatment; Long DL was proved more effective to the bolting of late bolting lines and those susceptive to DL. It was suggested that high SLL or 24 h DL suit fast propagation, and 108-144 μmol/(m²·s) of SLL and 16 h DL, easy to manipulate by fluorescent tube, be most suitable to bolting evaluation, which can shorten evaluation cycle and save energy as well.