Objective To investigate the predictive value of bone turnover markers such as PINP and β-CTX in Parkinson's disease (PD) complicated with osteoporosis. 105 patients with PD were enrolled and divided into osteoporosis group and non-osteoporosis group according to whether they were complicated with osteoporosis. Bone metabolism indexes such as 25- (OH) D, parathyroid hormone, osteocalcin, β-CTX, and PINP were detected in all patients, and the relationship between these indexes and the occurrence of osteoporosis was analyzed.Results 1. The proportion of oligotonic type, female proportion, PINP, osteocalcin and β-CTX in osteoporosis group were higher than those in non-osteoporosis group, while the level of 25- (OH) D in osteoporosis group was lower than that in non-osteoporosis group, and the differences were statistically significant. 2. Correlation analysis showed that the incidence of osteoporosis in PD patients was significantly positively correlated with osteocalcin (r=0.28, P=0.005), β-CTX (r=0.36, P=0.001), PINP (r=0.40, P < 0.001), and 25 (OH) D (r=-0.30, P=0.002), PINP/β-CTX (r=-0.56, P < 0.001) were negatively correlated. 3. Multivariate binary Logistic regression analysis showed that 25- (OH) D, (OR=0.95 95%CI: 0.84,1.07,P= 0.041), PINP/β-CTX (OR=0.90,95%CI 0.83,0.98,P=0.017) were risk factors for Parkinson's disease complicated with osteoporosis. 4.Receiver Operating Characteristic showed that 25- (OH) D combined with PINP/β-CTX had the largest area under ROC curve, with AUC=0.82, sensitivity =0.80, specificity =0.84, P < 0.001.Conclusion Serum 25- (OH) D level and PINP/β-CTX ratio are closely related to the occurrence of osteoporosis in PD patients. They have important predictive value in the occurrence of osteoporosis in PD patients, and the diagnostic value is higher when they are combined.