Abstract: Objective To study the role of tumor necrosis factor-alpha（TNF-α） and nitric oxide synthetase（NOS） in cardiac function of rats with sepsis.Methods A sepsis model of rats was established.The hemodynamics was monitored,the levels of TNF-α and nitric oxide（NO） were measured,and the activity of NOS was assayed.Results The levels of TNF-α and NO in cardiac muscle tissue reached their peaks 2h after the model was established,which were in accordance with the time of impaired cardiac function.The expression of cNOS was decreased while the expression of iNOS was significantly increased in cardiac muscle cells 6h after the model was established.Conclusion TNF-α and NO play an important role in cardiac function of rats with sepsis.The decreased expression of iNOS and the increased expression of cNOS in cardiac muscle cells may also contribute to the hypofunction of heart in rats with sepsis.