In this study, crude enzyme extraction method, diversity property and light influence of glutamate decarboxylase(Gad) in Brassica rapa L. ssp rapa were analyzed. Ultra Performance Liquid Chromatography(UPLC) method was used to measure the production in Gad catalyzed progress-- Gamma - aminobutyric acid(Gaba). Adding 1% cellulase solution at homogenization step could improve the enzyme activity up to about 70% as much. Meanwhile, when pH were 4.5-6 with the temperature of 55℃，enzyme had reached its maximum activity ,on the other hand Ca2+ and coenzyme Plp didn't have any contribution. Among the different developing stages of Brassica rapa L. ssp rapa, extration of sucking seedling apical meristem could generate more Gaba. In general, with proper conditions, the sucking seedling could be the most efficient material and easily obtained, thus having considerable prospects of industrial use.
