1561-4921 1735-8086 Objective: In this study, we examined the effect of different doses of bone morphogenetic protein 4 (BMP4) on CCE mouse embryonic stem cells (ESCs) viability and proliferation rates in order to improve the outcome of induction processes and make a system with highest viability and proliferation rates for further studies on BMP4 roles in multiple developmental stages. Materials and Methods: Expression of Oct-4 was studied and confirmed in this cell line immunocytochemically. Also, in order to evaluate the proliferation and viability rates in BMP4-treated cells, ESCs were cultured in Dulbecco's Modified Eagle Medium (DMEM) containing different doses of BMP4 (0, 0.01, 0.1, 1, 5, 25, 50 and 100ng/ml). The mean number of whole cells and living cells were considered as proliferation and survival rates respectively. Data analysis was done with ANOVA test. Results: The results showed that there were significant differences between the mean percent of viability between 1ng/ml and 0 ng/ml (control) and 50 and 100 ng/ml BMP4 (p≤0.01), as well as between 5 ng/ml and 0, 0.01, 0.1, 25, 50 and 100 ng/ml BMP4 (p≤ 0.02). Also, significant differences were observed in proliferation rates between 5 ng/ml and 0, 0.01, 0.1, 1, 25 and 100 ng/ml BMP4 (p≤0.01), 25 ng/ml and 0.01, 1 and 5 ng/ml BMP4 (p≤0.01), as well as between 50 ng/ml and 0.01 and 0.1 ng/ml BMP4 (p≤0.001). Conclusion: The results suggest that addition of 5ng/ml BMP4 had the best effects on the proliferation and viability rates of CCE mouse ESCs. Embryonic Stem Cells, BMP4, Proliferation, Viability 0 0 Mansoureh Movahedin mansoure@modares.ac.ir No Zohreh Makoolati No Mehdi Forouzandeh-Moghadam No