Objective To study the regulating effect of young Sca⁃1 bone marrow stem cell on epicardial cell senescence and its mechanism. Methods Young（Y）and old（O）Sca⁃1 bone marrow cell was co⁃cultured with old epicardial cell under hypoxia condition，respectively. The effect of Sca⁃1 bone marrow cell on epicardial cell senescence was detected by immunofluorescent staining，qRT ⁃PCR，and western blot，respectively. Results Compared to O Sca⁃1 bone marrow cell，Y Sca⁃1 cell decreased epicardial cell senescence，with decreased senes⁃ cent cell rate，decreased P27 gene and protein expression，and increased Sirt 1 gene and protein expression（P < 0.05）. More GDNF（Glial cell line⁃Derived Neurotrophic Factor）was found in Y Sca⁃1 cell group when compared to that in O Sca⁃1 cell group（P < 0.05）. The effect of Y Sca⁃1 cell on old epicardial cell senescence was lost when GDNF expression was blocked. Conclusion Young Sca⁃1 bone marrow stem cell decreases old epicardial cell senescence by GDNF.