Background: Overweight and obesity have become a common problem around the world, VietNam, localities. Therefore, we conducted this study to determine the prevalence and some related factors of overweight and obesity in Kindergartens at Vung Tau city. Objectives: To determine the prevalence and some related factors to overweight and obesity among primary school children at Vung Tau city in 2021-2022. Materials and methods: The descriptive cross-sectional study was performed in 540 children from 3 to 5 years old at 3 Kindergartens in Vung Tau city. They were measured height and weight. Their parents and teachers responded to prepared questionnaire. Results: The prevalance of overweight and obese children in Kindergartens at Vung Tau city in 2021 to 2022 is 23.15%, in that the obesity rate is 9.4%. The 5 year old group is 2.3 times highter rate overweght, obesity than the 3 year old group ( Cl 95%: 1.46-3.66). Children whose parents are overweight, obesity status and are interested in advertising food have the overweight or obese pervalance higher 1,9 times (Cl 95%: 1.32-2.74) and 1.48 times (Cl 95%:1.03-2.11) respectively than normal parents and is not interested in advertising food. Children who are gluttonous have a 2.24 times higher rate of overweight, obesity (Cl 95%: 1.46-3.43) than children with normal feeding. Children with outdoor and indoor activities for less than 1 hour a day, the rate of overweight, obesity are higher 1.74 times (Cl 95%: 1.10-2.74) and 1.6 times (Cl 95%: 1.03- 2.53) respectively than children with outdoor and in door activities more than 1 hour a day. The children who watch screens for less than 1 hour a day have 0.58 times (Cl 95%: 0.37-0.90) lower rate of overweght and obesity who watch more than 1 hour a day. Conclusion: The prevalence of overweight and obesity among preschool children in Vung Tau city is still high. Therefore, it is necessary to guide nutrition, exercise for parents, teachers to prevent overweight and obesity.