Objective: To investigate the incidence and influencing factors of abnormal body posture among urban primary school students in Yinchuan City, and to provide evidence for the prevention and treatment of abnormal body posture. Methods: A multi stage stratified cluster random sampling method was adopted to select 1 947 urban primary school students aged 7-12 years from 9 schools in Yinchuan City. Body Style(Model.S-8.0) instrument was used to screen abnormal body posture and questionnaire was designed to investigate related factors. Results: The comprehensive body posture score of urban primary school students in Yinchuan City was(22.07±2.87), and the detection rate of abnormal posturing was 71.29%；which varied significantly by gender, age, body mass index (BMI)( χ 2=9.84, 13.47, 6.46, P <0.05). Specially, the rate of girls (73.54%) was higher than that of boys( 69.07 %); the abnormal rate of children aged 7-8(68.24%) was lower than that of 9-10(72.17%) and 11-12(73.54%); obese children (74.91%) was higher than that of overweight (72.64%) and normal weight children(70.28%). The high and low shoulders (40.73%), pelvis forward (39.39%) and X/O legs (38.57%) were the most common indicators of abnormal posture; the composition of the overall body posture abnormalities was higher in mild (54.32%) than moderate (37.82%) and severe (7.85%).Multivariate Logistic regression analysis showed that girls( OR =1.23), being older(9-10 years old OR =1.89, 11-12 years old OR = 2.48 ), overweight ( OR =1.39) and obesity( OR =2.34), occasionally participate in physical exercise ( OR =2.96), exercise duration <30 minutes daily ( OR =2.77), video duration ≥2 h daily ( OR =2.84), almost no dairy products ( OR =1.79), almost no food Fish consumption ( OR =1.77), almost no vegetables ( OR =2.14), drinking carbonated beverages daily ( OR =2.97), and sleeping time <6 h daily ( OR =2.56) were the related factors of body posture development of urban primary school students( P <0.05). Conclusion The abnormal body posture of urban primary school students in Yinchuan City is prevalent, which is related to the timely length of physical exercise, nutrition, video screen and sleep duration, and should be paid enough attention.