Objective: To investigate whether buffalo rat liver cell-conditioned medium (BRL-CM) can be used as the culture medium of embryonic stem (ES) cells, and to get relatively pure neural precursor cells (NPCs) for treatment aim. Methods: Mouse ES cells were cultured in BRL-CM and medium contain leukemia inhibitory factor (LIF), respectively. NPCs were selectively cultured in serum-free medium. Alkaline phosphatase activity was visualized with NBT/BCIP and nestin antigen was detected with immunocytochemical methods. Results: BRL-CM could be used as an efficiency culture condition instead of LIF in ES cells culture. About 86% of cells derived from ES cells in the serum-free culture were NPCs. Conclusion: BRL-CM can replace LIF to use in ES cell culture. High purity of NPC can be induced from ES cells with serum-free culture method.