OBJECTIVE To understand the relationship between child malnutrition and social determinants among children under the age of 5 in China, and to provide evidence and useful information to help policy makers develop social policies to improve child nutritional status. METHODS Information of 2 434 children aged 0-5 was extracted from year 1991 to 2011 longitudinal survey data in the China Health and Nutrition Survey (CHNS) was extracted for analysis. Child underweight, child stunting, and child wasting were defined using World Health Organization Child Growth Standards for weight-for-age, height-for-age, and weight-for-height. Weight-for-age values, height-for-age values or weight-for-height values below 2 standard deviations were considered as underweight, stunting and wasting. World Health Organization igrowup software was used to calculate the prevalence of child underweight, child stunting, and child wasting. Multivariate Logistic regression model was used to analyze the relationship between child malnutrition and social determinants (household income, parents' educational level, living regions, and communities' urbanization level). RESULTS The prevalence of child underweight and child stunting were decreased by 64.8% and 67.8%, respectively from 1991 to 2011, while the prevalence of child wasting had remained at a relatively low level (below 5%). The problem of child underweight and stunting had been significantly resolved in China. Female children had better outcomes than male children on improving nutritional status. Among all the non-socio-economic determinants of child malnutrition, children with low height mother and children had inadequate protein intake were both risk factors of malnutrition. The social determinants significantly associated to child malnutrition included: living in the western regions and central regions, living in low level urbanization communities, with low household incomes, and low maternal educational levels. CONCLUSION In order to further decrease the prevalence of child malnutrition and alleviate the inequity of child health, we should pay more attention to the social determinants behind child malnutrition. Besides, social policies beneficial to child nutrition promotion need to be taken urgently, the important social policies suggested by the researchers included focusing on maternal and child dietary intake, improving household economic situation, improving maternal educational level, and balancing economic development and resource distribution between different regions in China.