To observe the effects of Hedysarum polysaccharides(HPS) on the apoptosis of bladder cancer cells mediated by mitochondrial pathway，and to explore the possible mechanism.Methods:T24 cells in log phase were collected and randomly divided into control group(conventional culture)，Hedysarum polysaccharides group(adding Hedysarum polysaccharides 0.8 μg/L)，SP600125 group(adding SP600125 10 μmol/L)，and combination group(adding Hedysarum polysaccharides) 0.8 μg/L，SP600125 10 μmol/L).MTT assay was used to detect cell proliferation.Double staining was used to detect the apoptosis rate.JC-1 method was used to detect mitochondrial damage in cells.Western blotting was used to detect expressions of cell-related proteins.Results:Compared with the control group，the absorbance values at 24，48 and 72 h，mitochondrial membrane potential，Bcl-2 protein expression were decreased，apoptosis rate，expressions of Bax and Caspase-3 proteins，p-JNK/JNK，p-c-Jun/c-Jun were increased in the HPS group(P<0.05)，and the absorbance values at 24，48 and 72 h，mitochondrial membrane potential，Bcl-2 protein expression were increased，apoptosis rate，expressions of Bax and Caspase-3 proteins，p-JNK/JNK，p-c-Jun/c-Jun were decreased in the SP600125 group(P<0.05).Compared with the HPS group，the absorbance values at 24，48 and 72 h，mitochondrial membrane potential，and Bcl-2 protein expression were increased，and apoptosis rate，expressions of Bax and Caspase-3 proteins，p-JNK/JNK，p-c-Jun/c-Jun were decreased in the combination group(P<0.05).Conclusion:HPS can inhibit the proliferation of T24 cells and promote their apoptosis by mediating the mitochondrial pathway.The mechanism may be related to the activation of the JNK/c-Jun signaling pathway.