To assess the effect of Nylestriol on postmenopausal osteoporosis in an attempt to reveal its mechanism.Thirty-seven month-old female New Zealand white rabbits were randomized into 3 groups (10 rabbits per group): treatment group [ovariectomized (OVX) + nylestriol (2 mg, monthly)], OVX control group (OVX + vehicle) and normal control group (sham operation + vehicle). Six months later, all rabbits were subjected to tetracycline labelling and then were killed. Under VIDAS system, bone turnover was assessed by bone histomorphometry.Bone volume trabecular (BV/TV), relative osteoid volume (OV/BV), osteoblastic index (OBI) and bone formation rate at tissue level [BFR(T)] increased in treatment group compared with OVX control group and (or) sham control group.Nylestriol can increase the number of osteoblast, which resulted in more bone matrix production and consequently converted the bone turnover of OVX rabbits to a positive balance situation. It indicated that Nylestriol was probably a stimulator for osteoblast recruitment and (or) proliferation.