Objective To investigate the effect of celastrol on proliferation, migration and epithelial-mesenchymal transition of nasopharyngeal carcinoma cells. Methods Human nasopharyngeal carcinoma cells HNE1 and CNE2 were treated with 1.8 μmol/L celastrol, and the cells treated with equal volume of dimethyl sulfoxide (DMSO) were used as control. The proliferation of HNE1 and CNE2 cells was detected by CCK-8 assay, the migration of cells was detected by cell scratch test, the clone formation was detected by cell colony formation assay, the adhesion and separation abilities of cells were examined by cell adhesion and separation experiments, and the expression of E-cadherin, β-catenin, N-cadherin and vimentin was detected by Western blotting analysis. Results Compared with the DMSO group, the proliferation of HNE1 cells was significantly decreased after treated with 1.8 μmol/L celastrol for 24, 48 and 72 h (all P<0.05), and the proliferation of CNE2 cells was significantly decreased for 48 and 72 h (both P<0.05); the migration ability of HNE1 and CNE2 cells was significantly decreased after treated with 1.8 μmol/L celastrol for 48 h (both P<0.05); and the clone formation of HNE1 and CNE2 cells was significantly decreased after treated with 1.8 μmol/L celastrol for two weeks (both P<0.05). The adhesion rate of HNE1 and CNE2 cells 1 h after treatment and separation rate 24 h after treatment in the celastrol groups were significantly lower than those in the corresponding DMSO group (both P<0.05). Western blotting analysis showed that the expressions of E-cadherin and β-catenin in HNE1 and CNE2 cells in the celastrol groups were significantly increased compared with the DMSO group, while the expressions of N-cadherin and vimentin were significantly decreased 6 h after treatment (all P<0.05). Conclusion Celastrol can inhibit the proliferation, migration and epithelial-mesenchymal transition of nasopharyngeal carcinoma cells HNE1 and CNE2.