ABSTRACT Objective: Rat embryonic fibroblasts (REFs) and rat bone marrow-derived mesenchymal stem cells (rat-BMMSCs) an be used as in vitro models for a variety of studies, including for degenerative diseases such as arterial ischemia, tissue engineering and development of induced pluripotent stem cells (iPSCs). Therefore, the further developments of the use of these two cells of great importance. Methods: The experiments were performed with Wistar rat, those with 15-17 d gestation (aged 32 w) as a REFs source and those aged 12 w as a BMMSCs source. Dulbecco's modified eagle medium (DMEM) was used for both cell cultures but with different media supplements. Proliferation ability was determined for both by calculating population doubling time (PDT). Characterization was performed by differentiation testing into osteocyte, chondrocyte and adipocyte cells by staining with Alizarin Red, Alcian Blue and Oil Red O and by an investigation of specific antigen characteristics using flow cytometry with positive CD90 and CD29 and negative CD34 markers. Results: Morphologically, the REFs and rat-BMMSCs had the same fibroblasts like shape. PDT was higher for the REFs than the BMMSCs (p<0.05), and both could differentiate into osteocytes, chondrocytes and adipocyte. The characteristics of the positive markers (CD29 and CD90) were higher in rat-BMMSCs than in REFs. Conclusion: In this study demonstrated that the explant method for REFs isolation and flushing method for rat-BMMSC isolation are both effective. It also showed that rat-BMMSC grow faster than REFs, and that both cells have the same differentiation ability as rat-BMMSCs but with different specific surface antigen characteristics.