AIM: To explore the mechanism of Periplaneta americana extracts (PA-CII-3) on anti-prostate cancer. METHODS: Prostate cancer cells PC3 in logarithmic growth phase were divided into a control group and an experimental group. The PA-CII-3 solutions of 1 000, 1 200, 1 400, 1 600, 1 800, and 2 000 μg/mL were added successively to the PC3 cells in experimental group, for screening out the appropriate drug concentration and best time to intervene by CCK-8 assay. And then, PA-CII-3 solution at 1 400 μg/mL was continuously intervened in PC3 cells for 72 hours. The cell proliferation ability was detected by CCK-8 assay and plate colony formation assay, the cell migration ability was tested by scratch wound assay, and the mRNA and protein expressions of ZAG were detected by Real time qPCR and Western blot methods, respectively. RESULTS: After PA-CII-3 intervention, the proliferation and migration abilities of PC3 cells were significantly inhibited, and the mRNA and protein expression levels of ZAG in PC3 cells were promoted. CONCLUSION: PA-CII-3 can play the role of anti-prostate cancer by inhibiting the proliferation and migration of PC3 cells, and upregulating ZAG.