Objective To investigate the effects of long-term oral administration of warfarin on cardiac valvular calcification. Methods Thirty-four patients who received oral administration of warfarin for over one year,and 18 disease condition-matched controls were selected. Echocardiography was performed to detect the valvular calcification. Some calcium metablic factors 〔calcium,phosphate,parathyroid hormone (PTH),alkaline phosphatase (AKP)〕,inflammation indicators 〔including high-sensitive C reactive protein (HsCRP),low density lipid cholesterol (LDL-C)〕,and calcification related matrix proteins 〔matrix Gla protein (MGP),osteopontin (OPN),Fetuin-A〕 were analyzed. The incidence of osteoporosis was recorded. Results The incidence of valvular calcification was 14.7% in warfarin group,and 11.1% in control group,with no significant difference between two groups. Serum MGP concentration was significantly lower in warfarin group 〔(3.7±1.9) nmol/L〕 than in control group 〔(11.0±4.3) nmol/L〕. OPN concentration was significantly higher in warfarin group 〔(154±56 ) μg/L〕 than in control group 〔(86±35) μg/L〕. Fetuin-A level was not different between the two groups. AKP level was significantly higher in warfarin group 〔(79±10) U/L〕 than in control group 〔(65±8) U/L〕. There was no difference in serum calcium,phosphate,PTH between the two groups. The patients suffering from osteoporosis accounted for 52.9% in warfarin group,higher than that in control group (38.9%). Conclusion Long-term oral administration of warfarin does not add the risk of valvular calcification,but increases the incidence of osteoporosis,which is not obviously associated with arterial inflammation,but might be associated with changes of MGP level.