Abstract: Objective To explore the mediation effect of appearance stress on the relationship between physical appearance perfectionism and mental health.Methods Seventy plastic and anesthetic surgery patients selected with random selection were surveyed with Physical Satisfaction Scale(PSS),Social Appearance Anxiety Scale(SAAS),Physical Appearance Perfectionism Scale(PAPS),Appearance Self-Esteem Scale(ASES),Appearance Stress Scale(ASS),and Body Image Concern Inventory(BICI)on the day before the operation.The data were analyzed with hierarchical regression and correlation.Results Significant correlations were found among worry,imperfection,appearance stress,and mental health(P<0.01).The appearance stress partially mediated the relationship between worry about imperfection and general physical satisfaction,facial satisfaction,and after introducing appearance stress,the standardized coefficient were reduced from 0.484 and 0.470 to 0.314 and 0.306,respectively,with significant differences(P<0.05).The appearance stress fully mediated the relationship between worry about imperfection and appearance self-esteem,and after introducing appearance stress,the standardized coefficient was reduced from 0.452 to 0.153,with a non-significant difference(P >0.05).The appearance stress did not mediate the relationship between worry about imperfection and social appearance anxiety,body image concern and figure satisfaction.Mediation of appearance stress was not existed between hope for perfection and mental health because there was no correlation between hope for perfection and appearance stress and mental health.Conclusion Physical appearance perfectionism could negatively influence mental health directly and also have negative effect on mental health indirectly through appearance stress.