【Abstract】Objective To investigate the expressions of TNF-α and superoxide dismutase (SOD) mRNA in myocardium of rats with obstructive jaundice (OJ). Methods The expressions of TNF-α and SOD mRNA were semi-quantitatively analyzed after amplification of cDNA in myocardium of the rats with OJ by RTPCR. Results The expression of TNF-α mRNA increased and that of SOD mRNA decreased in the myocardium of rats with OJ. The level of plasm TNF-α increased and SOD synthesis in myocardium decreased. Conclusion The injury of myocardium in OJ is correlated with increasing expression of TNF-α mRNA and decreasing expression of SOD mRNA.