Aim To investigate the effect of simvastatin on reactive oxygen species(ROS) expression in stretch stress(SS) induced macrophage cells. Methods RAW264.7 macrophage cells were cultured in vitro, treated with SS, or pretreated with simvastatin for 60 min and then stimulated with SS, the expression of ROS was detected by Hoechst33342 and H2DCFDA fluorescent probe, the fluorescence intensity of ROS was detected and the positive ratio of ROS was analysed by SPSS statistical software. The expression of NADPH oxidase 1(NOX1) was evaluated by Western blot.Results SS increased the expression of ROS in a time dependent manner, and the expression of ROS reached the most significant at 60 min(P<0.05). Simvastatin could inhibit the effect induced by SS in a concentration dependent manner, the inhibition effect of simvastatin was the most significant in 0.3 μmol/L(P<0.05). The expression of NOX1 was significantly inhibited by simvastatin after SS. Conclusion Simvastatin repressed ROS expression of RAW264.7 macrophage cells induced by SS through inhibiting the expression of NOX1.