Objective To investigate the incidence of obesity and the relationship between Hohhot preschoolers lifestyle,eating habits and childhood obesity,and provide evidences of obesity intervention strategy in pre-school children. Methods The method of stratified cluster sampling randomly was used to 2 800 selecte children in Hohhot physical measurements,height and weight.These children lifestyle,movement and eating habits of questionnaires were used to analyze the possible causes of childhood obesity risk factors. Results Hohhot overweight preschool children was 15.3%,obesity was 19.29%.Boy obesity was 23.8% which was higher than the rate of obese girls (14.6%);Urban childhood obesity rate was 22.7%,higher than the rural areas 13.6%;The incidence of childhood obesity in 3~6 years old age groups had no significant difference.Analysis showed:the too high mother weight gain was during pregnancy,high birth weight,artificial feeding,parental overweight,eat snacks,like eat meat,often eat fast foods,eating fast,exercise less time watching television and playing computer too long were children obesity risk factors. Conclusion Rates of obesity in preschool children is higher in this region,the incidence of childhood obesity is closely associated with the family environment,diet and genetic factors,early intervention should be strengthened to control children obesity.