［Objective］ This study investigated the toxic effects of the food contaminant 3-monochloropropane -1,2-diol (3-MCPD ) on the human renal tubular epithelial cell line (HK2) and examined the underlying mechanisms.［Methods］ Cell viability,morphology,mitochondrial function,enzyme activities,and apoptosis -associated proteins expressions were assessed using MTT assay,Hoechst 33342 staining,biochemical test kits and Western blot,respectively.［Results］］ Results showed a concentration -dependent decrease in cell viability when 3-MCPD was below 80 mmol/L for 24 h.Treatment with 20 and 30 mmol/L 3-MCPD over varying durations also led to a time -dependent reduction in cell viability.Additionally,3-MCPD at 20,40 and 60 mmol/L significantly increased LDH release,decrease mitochondrial membrane potential,and lowered ATP levels.Fluorescence microscopy revealed notable morphological changes,including bright blue fluorescence,nuclear shrinkage and apoptosis bodies.Furthermore,3-MCPD treatment downregulated the anti -apoptotic protein Bcl2,upregulated the pro -apoptotic protein Bax,and increased Caspase 9 and Caspase 3 activity in a dose -dependent manner.［Conclusion］ 3-MCPD exhibits toxic effects on HK 2 cells and induces apoptosis through a mitochondria -dependent pathway.