Objective:To prepare curcumin-loaded poly lactic-co-glycolic acid nanoparticles(Cur-PLGA-NPs),to characterize their physicochemical properties,and to study the in vitro release behavior and antitumor activity on human prostate cancer PC-3 cells in vitro. Methods:The Cur-PLGA-NPs were prepared by emulsification-solvent evaporation method. The transmission electron microscope was used to observe the particle appearance,Zetasizer instrument was used to detect the diameter,and ultracentrifugation was utilized to determine drug-loading rate and entrapment rate. Dynamic dialysis method was used to study the in vitro release behavior of Cur-PLGA-NPs. The antitumor activity on PC-3 cells was determined by CCK-8 method. Cells apoptosis and apoptosis rate were examined by using flow cytometry. Ultrastructural changes of cells were observed under the electronic microscopy,and compared to free Cur groups. Results:The optimal NPs were round with the nanometric size of(165.36 ± 24.21)nm,high entrapment rate of(83.05 ± 1.07)% and drug-loading rate of(10.87 ± 0.58)%. In vitro release test showed that release rate within 24 h of Cur-PLGA-NPs was 44.02%,and accumulating release rate was 84.81% at day10. After an effection of 5~40 μmol/L Cur and Cur-PLGA-NPs on PC-3 cells for 24~72 h,the inhibition rates of Cur and Cur-PLGA-NPs were 9.38%~83.62% and 10.56%~89.53%. CCK-8 experience revealed that there was significant difference between 20 μmol/L group and 40 μmol/L group compared Cur with Cur-PLGA-NPs(P < 0.05). Flow cytometry indicated that there was a significant difference between experiment group and control group(P < 0.05). Transmission electron microscopy showed that Cur-PLGA-NPs induced morphological change of apoptosis on PC-3 cells. Conclusion:The Cur-PLGA-NPs has good drug sustained-release capacity in vitro,and significantly improves the capacity of Cur to kill and inhibit the proliferation of PC-3 cells in vitro.