Background:Colorectal polyp,especially adenomatous polyp is considered to be a precancerous lesion of colorectal cancer;its occurrence is associated with lifestyle,food habits and genetic factors. Aims:To explore the impact of lifestyle and dietary factors on occurrence of colorectal polyps in Inner Mongolia area. Methods:A colonoscopy-based case-control study was performed. In 2012-2013,100 cases of colorectal polyps and 200 sex-,age-and nationality-matched polyp-free cases were recruited at the Second Affiliated Hospital of Baotou Medical College and were asked to complete a questionnaire including information on demography,lifestyle,and food habits,etc. Multivariate conditional Logistic regression analysis was used to estimate the possible colorectal polyp-related factors which were statistically significant in univariate analysis. Results:In lifestyle factors,after adjusted for age,sex,nationality,marital status and educational level,cigarette smoking (OR=1. 3,95% CI:1. 0-1. 8)and alcohol drinking(OR=1. 5,95% CI:1. 1-2. 0)were identified as the risk factors for colorectal polyps by Logistic regression analysis,while physical activity at least 4 times per week was a protective factor (OR=0. 6,95% CI:0. 4-0. 8). In dietary factors,wheat flour and rice(OR=1. 7,95% CI:1. 2-2. 8),fatty meat (OR=1. 4,95% CI:1. 2-1. 9),salt/pickled food(OR=1. 4,95% CI:1. 1-1. 8)and barbecue/fried food(OR=1. 6, 95% CI:1. 1-2. 3)were identified as the risk factors,while vegetables(OR=0. 6,95% CI:0. 4-0. 9)and fruits(OR=0. 5,95% CI:0. 4-0. 7)were protective factors after adjustment. Conclusions:Occurrence of colorectal polyps in Inner Mongolia area is associated with unhealthy lifestyle and food habits. Cessation of cigarette smoking and alcohol drinking, more physical activity,frequent consumption of vegetables and fruits,and less animal fat and processed food might decrease the risk of colorectal polyps.