Abstract: Objective To investigate the present situation of and relationship between medication adherence of warfarin and social support in patients with mechanical heart-valve replacement,and to provide evidence for improving medication adherence of the patients.Methods The social support scale and the modified Chinese Version Morisky Medication Adherence Scale(MMAS-8)were used and the information on 156 discharged patients with mechanical heart-valve replacement were collected through telephone interviews.Results The average score of medication adherence of warfarin was 7.25±0.93,and 88.4% of the patients had an upper-medium medication adherence.The total score of social support for the patients was 47.07±6.23.The medication adherence was positively correlated with the scores of social support and it's three dimensions among the patients(P<0.05).Multiple stepwise regression analyses showed that social support,age,as well as educational level were influencing factors of medication adherence of warfarin,and the most predominant factor for medication adherence was social support.ConclusionThe medication adherence of warfarin was influenced by social support in patients with mechanical heart-velve replacement,and the adherence could be improved by the medical staff through helping the patients to get more familial and social support.