Abstract: Objective: To investigate the clinical characteristics,diagnosis and treatment of ankylosing spondylitis complicated with primary hyperparathyroidism.Methods: The clinical characteristics of a patient with ankylosing spondylitis complicated with primary hyperparathyroidism were analyzed,and the relevant literatures were reviewed.Results: The severe osteoporosis,short course of disease,and kidney stone,hypercalcemia and hyperparathyroidism were the mainly clinical characteristics of patient with ankylosing spondylitis.Conclusions: Ankylosing spondylitis and hyperparathyroidism have similar or overlapping clinical characteristics,but their pathogenesis and treatment are different,which need to be differentiated.