Abstract: Objective To investigate the relationship between bone metabolism biochemical indexes and lumbar vertebrae fractures caused by postmenopausal osteoporosis. Methods A total of 80 patients with postmenopausal osteoporosis in our hospital were included in the study, among whom 37 patients with lumbar fractures were selected as observation group, 43 without were selected as control group. Bone mineral density and bone metabolism biochemical index were compared, and relation between bone metabolic biochemical indicators and osteoporotic lumbar vertebrae fracture after menopause was analyzed. Results There were no significant differences in bone density of lumbar spine and hip, serum calcium(Ca²⁺)and N-terminal-mid fragment of osteocalcin(N-MID)between the two groups(P>0.05). The 25-hydroxyvitamin D［25-(OH)D］ of the observation group was lower, and β-isomerized C-terminal telopeptide of type I collagen(β-CTX), N-terminal propeptide of type I collagen(PINP), bone alkaline phosphatase(BALP)were higher than those in the control group(P<0.05). Osteoporotic lumbar vertebrae fracture after menopause showed a positive correlation with BALP and PINP(P<0.05), a negative correlation with 25-(OH)D(P<0.05), and no correlation with β-CTX(P>0.05). Conclusion BALP, PINP and 25-(OH)D are closely related to postmenopausal osteoporotic lumbar vertebrae fractures, with BALP and PINP as risk factors and 25-(OH)D as protective factors.