【Objective】 To discuss the epidemiological situation and the risk factors in the pathogenesis for the functional constipation(FC) among school children in Shenzhen, and in order to provide a scientific basis of etiology and precaution for the school children. 【Methods】 A stratified, randomized study by cluster sampling using a questionnaire was employed with 1 786 children whose studying in primary school in Shenzhen, and the clinical data of these children diagnosed FC were analysed. 【Results】 The incidence rates for these functional constipation among school children is 5.49% in primary school in Shenzhen. Factors including the poor balanced diet, excessive intake of fried food, excessive intake of meat, did not eat or occasionally some vegetables, poor sleep quality, sweating much, anxiety, heredity and obesity were significantly associated with the presence of chronic constipation(OR＞1). 【Conclusion】 To start from the risk factors of school children's functional constipation and take some target actions and make early treatment could protect children from FC.