Purpose of investigation: We investigated various factors affecting bone mineral density (BMD) in young women and predictive factors of low BMD. Methods: Subjects were 105 nursing school students aged from 19 to 24 years old. Body weight (BW), pituitary hormones, sex steroid hormone and bone turnover markers were selected as factors. BMD was measured at the lumbar spine at L2-L4 by dual-energy X-ray absorptiometry (DXA). Results: BW (p = 0.002), serum N-terminal telopeptide of type 1 collagen (NTx) (p = 0.006) and bone specific alkaline phosphatase (BAP) (p = 0.02) were significantly correlated with BMD. For identification of the low BMD group, all subjects were divided into four groups on the basis of BW and NTx concentrations. In the group with BW under 51 kg and Ntx concentrations over 11 nMBCE/l, BMD was significantly (p = 0.0013) decreased compared with the other three groups. In this group, the ratio of women with a low BMD was significantly higher (p = 0.004) than the other groups. Conclusion: In young women, BW and bone turnover markers significantly affected BMD. Low BMD can be indicated using BW and NTx concentrations without measurement by DXA.