Objective To explore the parental perception of school-age children's body images and its influence factors among parents of school children in Changsha city,Hunan province,and to provide reference for childhood obesity prevention. Methods A survey with anthropometric measurement(height,w eight) was conducted among 2 224 elementary school students of grade 4-6 in Changsha city in April,2012. Body image was categorized based on the WHO 2007 body mass index(BMI) reference standard. The parental perception of the body image was examined with a questionnaire among the parents of the school children and the influence factors of the perception were analyzed with logistic regression. Results The body image rating scale results show ed that 56. 1% of the parents underestimated their children' s body image size. Multiple-factors logistic regression show ed that the risk factors for underestimating the children's body image was child's big body image(odds ratio [OR]= 35. 763,95% confidence interval [95% CI]= 23. 745-53. 863), w hile the protective factor was female parent(OR = 0. 623,95% CI = 0. 400-0. 969). Residing in the countryside(OR =1. 464,95%CI =1. 090-1. 966),with the child in senior grade(OR =1. 272,95%CI =1. 067-1. 517),and with the child having big body images(OR = 32. 089,95% CI = 16. 810-61. 255) were risk factors for parental underestimation of children's body image,w hile high parental education(OR = 0. 870,95% CI = 0. 773-0. 979) and overw eight or obese of the parents(OR = 0. 578,95% CI = 0. 403-0. 830) were protective factors. Conclusion Parental perception of school children's body image prensents an underestimation trend among the parents in Changsha. We should reinforce the communication and education in the parents to promote the correct evaluation on their children's body images for the control of overw eight and obesity in the school children.