Background Conjunctivochalasis (CCh) is one of the common age-related diseases,and its morbidity rate increases with age.So to investigate the prevalence of CCh and its related factors is of great significance to the prevention and treatment of CCh in China.Objective This survey was to investigate the morbidity rate of CCh in 50 years old or more population in Binhu district of Wuxi city,and to analyze the influence factors of CCh.Methods A cross-sectional study was carried out in the population aged 50 years or more from June to December in 2010 at Binhu district of Wuxi city by cluster random sampling method.The examinations included questionnaire,height and body weight measurement,and ophthalmologic examinations included visual acuity,refraction,and ophthalmoscope.Eyelid,conjunctiva,cornea status and position of CCh,place of inferior palpebral margin,eyelid edge tension,tear river status,anterior chamber,pupil and lens were examined under the slit lamp microscope.CCh was graded based on the criteria of Li Qingsong.Epi info procedure was used to establish database for the collection of data.Logistic multivariate regression analysis was performed for the analysis of risk factors of CCh using SPSS 17.0 software.Informed consent was obtained from each subject before any medical examination.Results Total 6 150 subjects were examined in 6 722 fifty years old or more persons,with the response rate of 91.50%.CCh was diagnosed in 1 667 eyes of 856 individuals,and the prevalence rate was 13.92%.The prevalence rate of CCh increased with aging(x2 =174.39,P<0.01).In 1 667 eyes with CCh,987 eyes were grade Ⅰ (59.21%),468 eyes were in grade Ⅱ (28.07%),202 eyes were in grade Ⅲ (12.12%) and 10 eyes were in grade Ⅳ (0.60%).The CCh mainly manifested dry,epiphora and blurred vision,with the occurrences of 22.63%,20.75% and 15.64%,respectively.Relaxed conjunctivas accumulated at temporal side+nasal side,nasal side or nasal+center+temporal side of the lower eyelid,with the proportion of 43.37% (723/1667),31.19% (520/1667) or 14.40% (240/1667).Superior corneal limbus type CCh was examined in 980 eyes,accounting for 58.79% of the affected eyes.Normal inferior lid margin tension was seen in 1 378 eyes,accounting for 82.66% in the affected eye,and the proportion with entroion and introversion type was 11.64%,which was higher than that of extroversion and ectropion type(5.76%).Abnormal tear fiver was found in 87.69% of CCh eyes,however,tear river was abnormal in all the grade Ⅲ and Ⅳ of CCh eyes.Significant differences were found in gender,educational level,history of hypertension and diabetes and body mass index between CCh patients and non-CCh patients(all at P<0.05).Conclusions CCh is a kind of common eye diseases among old population The prevalence rate of CCh is low in the population more than 50 years old in Binhu district of Wuxi city.The majority of CCh patients are grade Ⅰ and grade Ⅱ stage.The location and tension of inferior eyelid margin may be risk factors of CCh.Gender,culture degree,hypertension history,diabetes history,body mass index are possibly associated factors of CCh. Key words: Conjunctivochalasis; Epidemiology; Prevalence; Risk factor; Cross-sectional study