Objective To establish an improved culture method for obtaining oligodendrocyte precursor cells (OPCs) with high purity. Methods Mixed glial cells of cerebral cortex of newborn (1 to 2 d after born) Sprague-Dawley (SD) rats were primarily cultured for 8 d, and cells were cultured and purified by orbital shaking, differential adhesion and trypsin digestion in combination with defined culture media. Cell morphology was observed by light microscope with trypan blue staining. Two days after culture, cells were identified by immunofluorescence staining with A2B5 and DAPI, and purity analysis was conducted. Results It was observed by light microscopy that the cytomembrane of cultured cells was intact, with no cell injury. Purity analysis after immunofluorescence staining revealed that the ratio of number of A2B5-positive cells to that of DAPI-positive cells was 98.14%. Conclusion OPCs with high purity can be obtained by the improved methods of mixed glial cell culture and purification.