Abstract: To investigate the regulatory role of osteogenic growth peptide （OGP） in rat osteoblast-like cell.The isolated osteoblastic cells from calvaria bone of newborn rats were cultured in vitro. They were divided into two groups,one was added with OGP,the other was added with DMEM as the control. The medium was changed twice a week. On the 3rd、7th、10th、14th、21th culture-day，the activity of alkaline phosphatase、acid phosphatase，the contents of proteoglycan、collagen and Ca in the cells and extracellular-matrix were detected. The results showed that，the alkaline phosphatase activities and calcium level in the osteoblastic cells of OGP group on the3rd，7th, 10th，14th, 21th culture-day were significantly higher than those of the control groups （P＜0.01-0.05）, the collagen level of OGP group were 1.5 times higher than the control （P＜0.01）.It was concluded that OGP can greatly promote the proliferation of osteoblast-like cells and produce more bone tissues.

Key words: Osteoblastic cell, Osteogenic Growth Peptide （OGP）, Alkaline phos-phatase, Rat