Abstract: OBJECTIVE: To investigate the genotoxicity of di-phenyl-di- (2，4- chlorobenzohydroxamato) tin (DPDCT). METHODS：Ames test，chromosomal aberration test in Chinese hamster lung(CHL) cell and micronucleus test in mouse bone marrow were carried out. RESULTS：In Ames test，at concentration of 500 and 5 000 μg/plate，the reversal colonies in TA97 (±S9)，TA98 (±S9) ，TA100 (±S9) and TA1535 (+S9) were significantly increased (P＜0.01) compared with negative control. At concentration of 4.00 μg/ml，DPDCT induced a significant increase in number of chromosomal aberrations (P＜0.01) compared with solvent control at 24 h after administration without metabolic activation. Micronucleus test indicated DPDCT had no mutation effect on the rate of mouse micronucleated polychromatic erythrocytes at dose of 12.5-50.0 mg/kg. CONCLUSION：DPDCT showed genotoxicity in vitro，but not in vivo.

Key words: di-phenyl-di- (2, 4-chlorobenzohydroxamato) tin, genotoxicity, ames test, chromosomal aberration test, micronucleus test