Background. Renal cell carcinoma (RCC) is a common malignant tumor of the urinary system that seriously threatens human life and health. This study aims to explore the role of the traditional Chinese medicine Leptochloa chinensis in the pathogenesis of RCC. Meanwhile, this study also revealed the molecular biological mechanism of its antitumor activity. Methods. Human RCC 786-O cells were cultured in the RPMI-1640 medium, which contains different concentrations of Leptochloa chinensis (1,000, 3,000, and 9,000 μg/ml). MTT and flow cytometry assays were used to detect the viability of 786-O cells. Transwell and wound healing assays were used to detect cell metastasis. The protein expression was observed by western blot analysis. Results. Leptochloa can inhibit cell proliferation and induce apoptosis in RCC 786-O cells. In addition, Leptochloa can weaken the migration and invasion of 786-O cells. More importantly, Leptochloa can block the mTOR pathway by inhibiting the protein expression of p-mTOR. Moreover, the high concentration of Leptochloa chinensis has a better inhibitory effect on 786-O cells. Conclusion. The traditional Chinese medicine Leptochloa chinensis inhibits the viability and metastasis of 786-O cells by blocking the mTOR pathway.