Objective To investigate the inhibitory effect of dictamnine onepithelial⁃mesenchymal transition of human prostate cancer cells and its mechanism. Methods PC⁃3 cells of human prostate cancer were cultured； PC⁃3 cells were treated with dictamnine，and the semi⁃inhibitory concentration IC50 of dictamnine and its time⁃ dependent effect on the proliferation of PC⁃3 cells were detected by MTS. The invasion ability of cells was detected by transwell assay. The expression levels of E ⁃cadherin，vimentin，β⁃catenin and snail were detected by Western blot. The protein expression of snail and E⁃cadherin was detected by Western blot assay after pc⁃3 cells were treated with Wnt channel activator LiCl and dictamnine. Results Transwell experiment showed that compared with that in the control group，the invasion ability of PC⁃3 cells was decreased after the treatment with dictamnine（P < 0.01）. PCR and western blot showed that the expression of E⁃cadherin mRNA and protein was increased，while the mRNA and protein expression of vimentin and snail and β⁃catenin in nucleus were decreased（P < 0.01）. Compared with that in dictamenine group，the expression of snail mRNA and protein was increased and the expression of E⁃cadherin mRNA and protein was decreased in PC⁃3 cells treated with dictamnine and LiCl（P < 0.01）. Conclusion Dictamenine may inhibit pc⁃3 cell epithelial⁃mesenchymal transformation by inhibiting the Wnt/ catenin/Snail signaling pathway.