Objective:To culture rat cranial osteoblastic cells in vitro by modified explants culture. Methods:Primary osteoblastic cells were obtained from the calvaria of 3-day-old new-born SD rats. The calvaria were divided into small pieces and seeded on bottom of culture bottle. When osteoblasts crawled from the explants and confluented to monolayer,they were digested and aggregated by 0.25% trypsin and explants continued culturing. MTT,ALP activity and calcific nodule were analysized in different osteoblasts. Results:The cultured cells by this method were identified according to the osteoblastic bionomics. There were no statistical differences in MTT,ALP activity and calcific nodule among the osteoblasts. Conclusion:The modified explants method to culture primary osteoblasts could obtain large amount of cells and supply osteoblasts continuously.