[Objective] To learn the incidence rate as well as the contributing factors related to the simple obesity of preschool children in Dezhou City and to provide scientific evidence for the control of obesity among preschool children. [Methods] Adopting the method of whole group sampling at random and studying 578 children aged 3-6 in Dezhou; investigating all subjects' basic information (age, gender, height, weight, etc.); working out the incidence rate of child obesity and analyzing its related risk factors. [Results] The incidence rate of obesity of preschool children in Dezhou was 6.40%, of which, boys account for 8.44%, and girls account for 3.88%. The incidence rate of obesity was the highest in group of age 3. [Conclusion] The incidence rate of child obesity was higher among preschool children, which was related to gender, age, parents' obesity and life styles.