Abstract: Male wistar rats w ere eanployed in the present study.They were admistered successively 10mg methylmerculy（CH₃HgCl)/Kg weghtby subcutaneouinyctinn for 7 days On 15th day the brain tissues of rats w ere removed and DNA electrophoresis and analysis of flow crytcxn etry were perforned by malong use of tec;hnologis on clhzlar andm olecular biobgy. DNA was extracted from brain tissues ofCH₃HgCl-treatedrats A typi;alladder of DNA fragnments was seengel electrophoresis Neurons apoptosis rate and expression level of P⁵³ gene from CH₃HgCl-treated g mup were obviously higher thanthatfrom cnntrolgroup by analysis offlow cytome try(P<0.05). The experin ental results demonstrate that CH₃HgCl causes injury of brain neuron by inducing apoptosis P⁵³ gene participates in gene regulation in process of CH₃HgCl )-induced apoptos is of hrain neurons.