Objective:To study the influence of proteasome inhibitor lactacystin (LAC) and carboplatin in proliferation and apoptosis of the human ovarian cancer SKOV3 cells in vitro ,and to clarify the mechanisms. Methods:The SKOV3 ovarian cancer cells were cultured in vitro ;0,2.5,5.0,10.0 and 20.0 μmol· L-1 LAC were used to intervent the SKOV3 cells for 48 h;5 μmol·L-1 LAC was used to intervent the SKOV3 cells for 0, 24,48,and 72 h;the SKOV3 cells were divided into control group (treated without medical intervention),LAC group (treated with 5 μmol · L-1 LAC), carboplatin group (treated with 10, 20, 40 and 80 μmol · L-1 carboplatin),LAC and carboplatin group (treated with 5 μmol· L-1 LAC and 10,20,40,and 80 μmol· L-1 carboplatin,respectively).MTT method and FCM were used to detect the inhibitory rates of proliferation and apoptotic rates of the SKOV3 cells in various groups.Results:The MTT test results showed that the proliferation of the SKOV3 cells were inhibited with the prolongation of time and increasing of LAC concentration;the half inhibitory concentration (IC50 )of LAC at 48 h was 5.36 μmol · L-1 ;compared with carboplatin group,the inhibitory rates of proliferation of SKOV3 cells in LAC and carboplatin groups were significantly increased (P <0.05).The IC50 of carboplatin was dropped from 58.08 μmol·L-1 to 18.37 μmol·L-1 .The FCM results showed that with the prolongation of treated time of LAC,the apoptotic rates of SKOV3 cells were increased;compared with carboplatin group and LAC group,the apoptotic rate of cells in LAC and carboplatin group was increased (P <0.05).Conclusion:LAC can inhibit the proliferation of the ovarian cancer SKOV3 cells and induce the apoptosis, and LAC can enhance the inhibitory effect of proliferation of carboplatin on the ovarian cancer SKOV3 cells.