Objective To explore the prevalence of weight misperception and related influencing factors among adult residents in Guangdong province so as to provide information for prevention and control on weight misperception.Methods A multi-stage stratified random sampling method was used to select the sample.Forty-two streets/villages were selected from 21 counties/districts through randomly sampling.Four communities were then chosen from every selected town or district,followed by 40 families chosen from every village or community.Questionnaire was used to collect data on weight perception and its related risk factors.SPSS 16.0 was used for data analysis.Results There were 6625 respondents participating in the study.Out of them,50.2％ participants misperceived their weight status,among which 35.9％ of them underestimated while 14.3％overestimated their weights.Females aged 15-24 were more likely to overestimate weights than males in the same age group (38.6％ vs.18.5％),while males were more likely to underestimate weights than females (25.8％ vs.8.5％ ).The prevalence of underestimation on weights increased with the increase of age in both males and females but the prevalence of overestimation on weights decreased.Data from multivariate results from logistic analysis showed that rural residents,males,being elderly,residents with low education level,manual occupations (agriculture,forestry,animal husbandry and fishery),low family income and with anxiety were the major risk factors on underestimation of weight.However,factors as being urban residents,females,adolescents,minority and never having received weight measurement etc.were the major risk factors of overestimated on weight.Conclusion Misperceptions of weight status in Guangdong province exhibited a high prevalence with complicated influencing factors,calling for more psychological research to be carried out to prevent and reduce the misperceptions on weight status.