〔Abstract〕 Objective To explore effects of tetrandrine(TET) on growth, movement of tongue squamous cell SCC9 and tumorigenesis in nude mice and its mechanism. Methods Human tongue squamous cells SCC9 were culturedin vitro. They were divided into blank group, low-dose TET group(TET 2.5 μmol/L), medium-dose TET group(TET 5μmol/L) and high-dose TET group(TET 10 μmol/L). And these groups were pretreated with corresponding doses of TET. Cell growth was detected by colony formation assay. The apoptosis was detected by flow cytometry. Cell invasion was detected by Transwell. The expression levels of Ki67, Caspase-3, vascular endothelial cell growth factor(VEGF), PI3 K, p-PI3 K, AKT, p-AKT, mTOR and p-mTOR proteins were detected by Western blot. A total of 60 nude mice were selected. 0.002% 4-nitroquinoline-1-oxide natural drinking water was applied to feed them for 36 weeks to establish animal models of tongue squamous cell carcinoma. They were given low-dose TET[12.5 mg/(kg·d)], medium-dose TET [25 mg/(kg·d)]and high-dose TET [50 mg/(kg·d)] for gavage treatment. 29 d later, tumor weight was detected. The expression of Ki67, caspase-3 and VEGF in tongue squamous tissues was detected by immumohistochemical staining. Results Compared with those in blank group, colony formation rate of tongue squamous cells, number of invasive cells per unit area, expression of p-PI3 K, p-AKT and p-mTOR protein were significantly decreased after treated with TET. The above indexes were the highest in high-dose TET group, followed by medium-dose TET group and low-dose TET group. Compared with those in blank group, there was no significant difference in expression levels of PI3 K, AKT and mTOR protein among the other three groups. Compared with those in blank group, expression level of Caspase-3 protein was significantly increased after treated with TET. The above index was the highest in high-dose TET group, followed bymedium-dose TET group and low-dose TET group.In vivoexperiments of mice showed that compared with those in blank group, tumor mass of nude mice, expression level and positive rate of Ki67 protein and VEGF were significantly decreased after gavage treatment with TET(P<0.05), and the higher the gavage concentration, the lower the above indexes. Compared with those in blank group, expression level and positive rate of Caspase-3 protein in nude mice were significantly increased after gavage treatment with TET(P<0.05), and the higher the gavage concentration, the higher the above indexes. Conclusion TET can inhibit growth and movement of tongue squamous cells by inhibiting PI3 K/AKT/mTOR signaling pathway, and promote apoptosis of tongue squamous cells, which shows concentration-dependence within certain concentration range.