OBJECTIVE: To understand the situation and incidence of early adverse reactions after zoledronic acid injection for postmenopausal osteoporosis, and to analyze the correlation between bone mineral density, combined fracture, application of calcium, bone resorption inhibitors and early adverse reactions. METHODS: Fifty-eight patients treated with 5 mg zoledronic acid injection for postmenopausal osteoporosis between 2009 and December 2010 were followed up, and the adverse reactions and their incidence were recorded within 30 days after the administration of the drug and analyzed. RESULTS: The early adverse reactions after zoledronic acid administration were mainly fever, muscle pain, flu-like symptoms, headache, arthralgia and other symptoms, and their incidence rates were 48.3%, 25.9%, 31.0%, 41.4% and 24.2%, respectively. The overall rate of adverse reactions was 60.3%. Most of them were transient, and all of them resolved completely within 30 days after drug administration. There was no statistically significant difference between the difference in bone density, whether or not combined fracture and the incidence of adverse reactions; there was a statistically significant difference in the incidence of headache, muscle pain and joint pain in the reverse direction whether or not calcium was applied before treatment. There was a statistically significant difference between patients with or without history of application of bone resorption inhibitor application drugs before treatment and the incidence of fever, headache, muscle pain, and arthralgia after treatment. Conclusion: 5mg zoledronic acid injection has high safety in the early stage of treatment, the symptoms of adverse reactions are mostly transient, and the incidence of early adverse reactions is not related to bone density and combined fracture, but may be related to calcium and bone resorption inhibitors. Preventive treatment should be promptly administered before and after the drug, and no serious sequelae should be observed in the early stage.