Objective　To investigate the activation of human T cells with superantigen SEA. Methods　T cells proliferation, IL-2 production, DNA synthesis, cell phenotype and apoptosis induced by the SEA in the first or restimulation were detected. Results　 It was shown that 100 ng/mL was the optimal activation concentration, IL-2 production arrived at top level in the third day, SEA activated CD4+ and CD8+T with the same degree, T cells start apoptosis in response to SEA restimulation within 24 hours and apoptosis disappeared through addition of rhIL-2. Conclusions　 There were correlation between activation and SEA concentration or stimulation period； SEA activated both CD4+ and CD8+T cells without change the cell phenotype.