Objective To investigate the sleep quality of pacemaker implanted patients,to analyze the relationships among neuroticism,positive psychological capital and sleep quality,and to examine the potential mediating effect of positive psychological capital on the relationship between neuroticism and sleep quality. Methods Using convenience sampling, a total of 178 pacemaker implanted patients were interviewed and analyzed in two tertiary hospitals of Shandong province. They were assessed with Big Five Inventory,The Positive Psycap Questionnaireand Pittsburgh Sleep Quality Indexfor the evaluation of neuroticism,positive psychological capital and sleep quality.The Process macro was used to test the mediating effect. Results The mean score of PSQI in patients with pacemaker implantation was (8.48± 4.50), and 71.3％of them had sleep problems.The scores of neuroticism had positively correlated with the PSQI scores(r=0.31, P<0.01), the scores of positive psychological capital had negatively correlated with the PSQI scores(r=- 0.39, P<0.01).The confidence interval from Bootstrap output indicated positive psychological capital played a mediating role between neuroticism and sleep quality (95％CI:0.06-0.23), mediation effect was 0.14, the percentage of mediation effect in total effect was 43.75％. Conclusions The relation of positive psychological capital to neuroticism and sleep quality among pacemaker implanted patients are intimate.Positive psychological capital could mediate the relationship between neuroticism and sleep quality. It is suggested that nurses can improve the patient′s sleep by enhancing the intervention of positive psychological capital according to the personality characteristics of patients.