Abstract: The effect of injection rotenone on the brain levels of dopamine (DA) and its metabolites (DOPAC and HVA) in C57BL/6N mice was studied.The mice were given two subcutaneous injections of rotenone (10 mg/kg) at 2 h interval between injections,and were killed at 8 hr after the second injection.The brain tissue was weighed and placed in a 5 mL tube containing ice-cooled perchl-oric acid (2 mL,0.4 mol/L),homogenized for 1 min at 20 000 r/min using an Ultra Turrax and centrifuged at 16 000 g for 12 min at 4℃.The supernatant was passed through a 0.2 μm filter and either directly analyzed or frozen at -70℃ until analysis.The DA and two of its metabolites were determined by HPLC with ECD.Results showed the percentage of increasing reached 40.5% (DA),544.4% (DOPAC),and 168.2% (HVA) as compare to the control (P<0.01) after the last injection.The rotenone has been suggested a potential nueurotoxicant that induced dopaminergic neurons to release dopamine and its metabolites in the mice.