Abstract: Objective　Alkaline phosphatase (ALP) and osteocalcin(OC) are the markers of newbone formation. Quantitative study of ALP and OC in the process of newbone formation helps to understand the ongoing of this cascade and contributes to make diagnosis in clinical treatment.Methods　8-week-old male C57BL/6J mice and primary osteoblasts from neonatal C57BL/6J mice calvaria were used in this experiment. HE staining, Northern blot and RealTime PCR methodswere employed to detect the histo- logical changes and the expression pattern of ALP and OC.Results　In vivostudy showed that after fracture the expressions of both ALP and OC kept on increasing whichwere peaked on the 10thday, then started decreasing gradually.In vitrostudy on pri- mary osteoblasts showed that the expressions of ALP and OC reached peak on the 14thday in differentiation culture medium and started decreasing from this time point till the 21stday.Conclusion　The expression of ALP and OC in the process of new bone formation parallels with the development of osteoblasts,it increases with the differentiation of osteoblasts and becomes decreasing with the maturation of osteoblasts. The reciprocal relationship between the expression pattern of ALP and OC and development of osteoblast helps to maintain homeostasis.

Key words: alkeline phosphatase, osteocalcin, new bone formation