Objective:To investigate the effect of Rapamycin on epithelial-mesenchymal transition (EMT) of LoVo colonic adenocarcinoma cells in vitro. Methods:Cultured LoVo colonic adenocarcinoma cells were divided into three groups: negative control group, EMT-inducing group (TGF-β1) and EMT-interfering group (TGF-β1 plus Rapamycin). E-cadherin expression in LoVo cells was detected by Western Blot, while the expression of vimentin was evaluated through immunocytochemistry. The Snail mRNA in LoVo cells was examined by RT-PCR. Results: TGF-β1 induced LoVo cell switching from polygonal to spindle-shaped. TGF-β1 enhanced the expression of vimentin, but lowered the level of E-cadherin. In contrast, Rapamycin impaired the transition induced by TGF-β1. Rapamycin dramatically abrogated TGF-β1-induced vimentin expression and restored E-cadherin expression in LoVo cells. Rapamycin significantly repressed the up-regulation of Snail mRNA expression induced by TGF-β1. Conclusion: Rapamycin dramatically abrogated TGF-β1 induced Snail mRNA expression in LoVo cells, hence inhibiting the EMT of these cells in vitro.