Objective To investigate hospitalized patients' attitude to participate in patient's safety,to explore its influencing factors,and to provide scientific suggestions to encourage patients' involvement in medical safety.Methods A convenience sample containing 140 patients from a level three class A hospital and 108 patients from a level two class A hospital in Shanghai were investigated using " Questionnaire of Perceived Effectiveness and the likelihood of Petients' Participation in Medical Safety",which was designed by Hibbard JH and had been cross-culturally Chinesized in this research.Results Total score and average score of patients' willingness for involvement in patient safety were 0-66 (full score 66) and (58.60 ± 8.71).Relative factor is patients' satisfaction of the safe surroundings provided by hospital (r =0.149,P ＜ 0.05).Total score and average score of patients'perceived effectiveness of involvement in patient safety was 20-66(full score 66),and (59.53 ± 7.98).Relative factor was patients' satisfaction of the safe surroundings provided by hospital (r =0.174,P ＜ 0.05).Patients' willingness for involvement was positively correlated withperceived effectiveness (r=0.781,P ＜ 0.01).Conclusions Most of the patients are motivated in patient's safety,yet they have different attitudes to various participant modes.Medical staff should enhance patient-safety education so as to make patients become real cooperator in medical activities.