Objective:To examine whether AngⅡ preconditioning improves the anti-apoptotic ability of bone marrow mesenchymal stem cells (MSCs),and if so,what is its possible mechanism. Methods:MSCs cells from rats were pretreated with Ang Ⅱ , and apoptosis of MSCs was induced by H2O2 or hypoxia combined serum deprivation (Hypoxia/SD) method. Cell viability and apoptotic proportion were detected by lactate dehyarogenase (LDH) release, methye thiazolye telrazlium (MTT) assays and Hoechst 33342 staining. Annexin V-FITC assay was performed for quantification of apoptosis rate. The mitochondrial transmembrane potentia (ΔΨm) was detected by a flow cytometer using ΔΨm specific stain Rhodamine 123. Results:AngⅡ preconditioning significantly reduced H2O2- or Hypoxia/SD-induced cell damage,increased cell viability,reversed Hypoxia/SD-induced mitochondrial membrane potential reduction. Both of ERK1/2 inhibitor U0126 and Akt inhibitor LY294002 significantly attenuated the the protective effects of AngⅡ preconditioning on the viability and apoptosis rate of MSCs. Conclusion: AngⅡ preconditioning prevents MSCs from apoptosis,and Akt and ERK1/2 signalling pathway may be implicated in the effect of AngⅡ.