Objective:To study the effects of drug-containing serum of Suoquan Pill on proliferation and differentiation of mouse embryonic stem cells(ESCs)and Nanog gene expression. Methods The embryonic stem cell line derived from 129 mice was selected. The cultured cells were divided into the blank group,Jingui Shenqi Pill group,Suoquan Pill groups with low-,middle- and high-dose. The blank group was treated with blank serum of rats at concentration of 10%,the Jingui Shenqi Pill group was treated with the drug-containing serum at concentration of 10%. The drug-containing serum of Suoquan Pill was obtained from rats that treated with Suoquan Pill for intragastric administration at daily dose of 0.585,1.17 and 2.34 g·kg-1·d-1 respectively. The Suoquan Pill groups with low-,middle-and high-dose were treated with the corresponding drug-containing serum at concentration of 10%. The effect of Suoquan Pill on ESCs proliferation was detected by flow cytometry. The effect of drug-containing serum of Suoquan Pill on differentiation of DMSO induced ESCs was observed by inverted phase contrast microscope. The Nanog mRNA expression in ESCs was detected by fluorescent quantitative PCR and the Nanog protein expression was detected by flow cytometry.  Results: Compared with the blank group,the drug-containing serum of Suoquan Pill with middle-and high-dose could promote ESCs proliferation(P<0.01),the drug-containing serum of Suoquan Pill with low-and high-dose could significantly increase Nanog mRNA expression in ESCs(P<0.05,P<0.01),and the drug-containing serum of Suoquan Pill with middle-and high-dose could significantly up-regulate Nanog protein expression in ESCs(P<0.05,P<0.01). Compared with the blank group,the drug-containing serum of Suoquan Pill with high-dose could promote the differentiation of DMSO induced ESCs.  Conclusion: Suoquan Pill can promote ESCs proliferation and differentiation of DMSO induced ESCs,which may be associated with the up-regulation of Nanog expression.