Objective To investigate the significance of fibroblast growth factor 23 in metabolic bone disease of prematuriy.Methods 60 patients who had been treated in our hospital from March 2016 to March 2017 were included in this study.Blood biochemistry was examined two weeks after birth,and values of blood phosphorus, serum calcium and alkaline phosphatase were recorded. Serum levels of 25 hydroxyvitamin D3,parathyroid hormone and fibroblast growth factor 23 were detected two weeks after birth. 20 premature infants with metabolic bone disease were selected as a study group. 40 infants without metabolic bone disease were treated as a control group. Two weeks after treatment,the above indicators were measured and compared in the study group. Results Serum levels of 25 hydroxyvitamin D3,parathyroid hormone and fibroblast growth factor 23 were compared between the two groups 2 weeks after birth,the difference was statistically significant(P<0.05).Levels of serum parathyroid hormone and fibroblast growth factor 23 in the study group were not statistically significant after treat-ment(P > 0.05). Levels of 25 hydroxy vitamin D3 in the study group had statistically significant after treatment (P<0.05).Conclusions Early detection of fibroblast growth factor 23 can reflect metabolic bone disease in pre-term infants.It suggests that vitamin D should be adequately supplemented in early.