Objective To investigate the perceived coercion of involuntary inpatients with mental disorders in the process of admission and during hospitalization， and to explore its influencing factors. Methods A total of 254 involuntary inpatients with mental disorders were selected from 6 closed wards of Xuhui district branch of Shanghai Mental Health Center affiliated to Shanghai Jiao Tong University School of Medicine， from March to August 2017 according to Article 30 of the "Mental Health Law". During the third week after admission， self-compiled basic information questionnaire， Brief Psychiatric Rating Scale（ BPRS），MacArthur Perceived Coercion Scale（ MPCS）， and Coercion Experience Scale（ CES） were used to investigate the enrolled inpatients. All the patients were divided into two groups according to whether they had solicited their opinions before admission. There were 115 cases in solicitation group and 139 cases in non-solicitation group. SPSS 22.0 software was used for statistical analysis. Independent sample Mann-Whitney test， Kruskal- Wallis test and Chi-square test were used for inter group comparison. Bonferroni method was used to correct the post event pairwise comparison of significance level. Correlation analysis was used to understand the correlation between MPCs， CES and BPRS symptom score， and regression analysis was used to explore the influencing factors of coercion score. Results （1） Compared with the environmental limitations of psychiatric wards， the patients' perception of coercion was more due to the restriction of right to make choice and decision by themselves；（ 2） For patients who had not been asked for their opinions at admission， the total score of MPCS ［4.00（2.00，5.00） vs. 1.00（ 0，2.00），Z=8.592，P＜0.01］， total score of CES［ 52.00（39.00，81.00） vs. 44.00 （34.00，56.00），Z=3.236，P＜0.01］ and dimension score［ limitation of rights 13.00（9.00，27.00） vs. 9.00（9.00， 15.00），Z=3.746，P ＜ 0.01］ were significantly higher than those in the solicitation group at admission；The passive score was 14.00（ 10.00，24.00） vs. 12.00（ 9.00，18.00），Z=2.861，P＜0.01； The negative environment score was 9.00（ 6.00，13.00） vs. 8.00（ 6.00，10.00），Z=2.000，P＜0.05； The score of negative reaction was 4.00 （2.00，6.00） vs. 3.00（2.00，5.00），Z=2.706，P＜ 0.01）， which were all higher than those in the solicitation group. （3） Lack of consent before admission， public security agency delivery， and higher education level were positive influencing factors of MPCS total score（ F=25.076，P＜0.01）. Experienced restraint protection， severe BPRS thinking disorder and high coercion experience at admission were positive influencing factors of CES total score （F=5.135，P ＜ 0.01）. Conclusions Coercion experience is common in patients with mental disorders during admission and hospitalization. This subjective negative experience is related to various factors. More attention should be paid to this experience in clinical practice， and targeted measures should be taken to reduce patients' perception of coercion.