OBJECTIVE To investigate the effect of succinate dehydrogenase complex subunit A (sdha)gene on cell proliferation,cell cycle and apoptosis of mouse hepatic cell line BNL CL.2 cells. METHODS The BNL CL.2 cells were transfected by two kinds of sdha-shRNA lentivirus to knockdown sdha gene. The infection efficiency of BNL CL.2 cells infected with lentiviral vectors was analyzed by flow cytometry. The expression of sdha gene and SDHA protein was detected by real-time PCR and Western blotting,respectively. The effect of sdha gene on cell proliferation of BNL CL.2 cells was examined by growth curve,while cell cycle and apoptosis were analyzed by flow cytometry. RESULTS The infection efficiency of BNL CL.2 cells in sh-control group and in sdha-shRNA group was above 80%. Compared with sh-control group,the expression of sdha gene in BNL CL.2 cells infected with sdha-shRNA lentivirus was decreased by about 20 times(P<0.01),the expression of SDHA protein was decreased by about 10 times(P<0.01),and the growth rate was about 70%that of sh-control group(P<0.05). The cells were arrested in S phase,and the percentage of cells in S phase was 0.74 times that of sh-control group(P<0.01). The percentage of cells in G0/GI phase was 1.17 times that of sh-control group(P<0.01). The percentage of cells in G2/M was 1.37 times that of sh-control group(P<0.01). But there was no obvious difference in the apoptosis rate. CONCLUSION The reduced expression of SDHA protein can inhibit the proliferation of mouse hepatic cells,and the inhibitory mechanism may be cell cycle arrest. There is possibly no relationship between inhibition and cell apoptosis.