【Abstract】Objective To observe the effect of low molecular weight heparin (LMWH) on calcium-phosphate metabolism in maintenance hemodialysis (MHD) patients. Methods We recruited 78 patients who had undergone hemodialysis for at least three months without hemorrhage risk, and were randomly divided into LMWH treatment group (38 cases) and unfractionated heparin (UFH) treatment group (40 cases). Serum calcium, phosphate, parathyroid hormone (PTH) and alkaline phosphatase (AKP) were measured. Changes of bleeding, coagulation status in the extracorporeal circuit, and adverse effects were recorded. Results In the 12 months of treatment, lower serum levels of phosphate and PTH were observed in LMWH group (P＜0.05 for phosphate and PTH), but not in UFH group (P＞0.05). Serum calcium and AKP had no differences between the 2 groups (P＞0.05). Bleeding was more in UFH group than in LMWH group (P＜0.01), leading to the change of heparin treatment in 6 cases in UFH group. Conclusion LMWH used as the anticoagulant in hemodialysis may associate with the improvement of calcium-phosphate metabolism in MHD patients.