Objective: To analyze relationships between levels of 24 hour movement (physical activity, screen time and sleep) and childhood obesity in students aged 7-18 years. Methods: This study used data from students aged 7-18 years in the 2015 China health and nutrition survey, and assessed levels of physical activity, screen time and sleep based on the Canadian 24 hour Movement Guidelines for Children and Youth. Associations between levels of 24 hour movement and childhood obesity were assessed using multivariable Logistic regression models. Results: The overall rate of overweight and obesity was 21.56%. Proportions of students meeting the guidelines for physical activity, screen time, sleep and three behaviors combined were 24.84%, 38.69%, 57.08%, and 6.77%, respectively. After adjusting for age, sex, location of residence and nationality, students meeting the sleep guideline were less likely to be overweight and obese than those who did not(OR=0.73)， students meeting both sleep and screen time guidelines had a lower risk in overweight and obesity than those met neither guidelines(OR=0.58)(P<0.05). However, other behaviors and behavior combinations showed no significant associations with overweight and obesity. Conclusion Only a small proportion of students met all three 24 hour movement guidelines. Ensuring adequate sleep and limiting excessive screen time may be an important strategy for childhood obesity prevention and management.