The effects of the appropriate time of planting, plant physiological state of treatment and vacuum infiltration time on genetic transformation frequency of vacuum infiltration were studied with Agrobacterium tumefac/ens strain GV3101 which was contained hygromycin B phosphotransferase gene (hyg) and CaMV gene Ⅵ in Chinese cabbage (B. campestris L. var. purpurea and var. utilis). The PCR assay of transforming plants showed that the target genes had transformed into Chinese cabbage successfully. This result indicates that the vacuum infiltration transformation is a convenient, quick, effective and non-tissue-cultural transformation method. The suitable physiological state for the vacuum infiltration in Chinese cabbage was healthy and strong plants, finishing flower bud differentiation, internode beginning to elongate, but not completely bolting. The mean of the leave length of the second, third and forth was above 6cm and that of the leave width was above 3cm, stem thickness was above 4mm with eight to nine leave. The best planting time of cv. "Sijiu" and "Erzaozi" in greenhouse was on February 16th and vacuum infiltrating was done on April 12nd. The transformation frequency was as high as 1.62%～2.0% when intermittently drawing a vacuum for three times "1min" with a vacuum pump whose suction capacity was 14.4m3•ha-1. Different flower bud treatment pattern affected the transformation frequency remarkably.