Objective: To study the protective roll of neuregulin-1 (NRG-1) on high glucose caused myocardial cell injury in rat’s embryo H9c2 myocardial cells with its mechanism. Methods: Cultured rat’s embryo H9c2 myocardial cells were divided into 5 groups:①Control group,②High glucose (HG) group, containing glucose 33 mmol/L,③HG+NRG-1 10 nmol/L (N1) group,④HG+NRG-1 50 nmol/L (N2) group and⑤HG+NRG-1 250 nmol/L (N3) group. All cells were treated for 24 hours. Myocardial cell survival rate was measured by CCK-8 method, intracellular reactive oxygen species (ROS) level and the apoptosis rate were detected by lfow cytometry, enzymes activities of CK, LDH, SOD and MDA content were examined, proteins expressions of NRG-1 receptor as ErbB2 and ErbB4 were assessed by Western blot analysis. NRG-1 treated myocardial cell apoptosis in type II diabetic cardiomyopathy rats was observed by Tunel staining. Results: Compared with HG group, from N1 group to N3 group, myocardial cell survival rates were increased from (63.33±3.56) %to (85.88±4.55) %, ROS levels decrease form (33.75±4.23) % to (15.88±4.55) %, apoptosis rates reduced from (36.44±4.86) % to (14.77±4.21) %, receptor expressions of ErbB2 was elevated from (0.26±0.04) to (0.84±0.03) and ErbB4 was elevated from (0.39±0.03) to (0.72±0.04), allP<0.05; enzymes activities of CK, LDH and MDA content were gradually decreased and SOD activity was gradually increased, allP<0.05. NRG-1 treated myocardial cell apoptosis in type II diabetic cardiomyopathy rats was also obviously reduced. Conclusion: NRG-1 could increase the survival rate and reduce the oxidative stress injury and apoptosis of cultured rat’s embryo H9c2 myocardial cells in HG condition which might be related to NRG-1 binding to ErbB2/ErbB4 molecules in the cells.