The research aimed to identify the physical development (weight and height), over weight and obesity status of school children of two primary schools in Hanoi city. A cross-sectional study was conducted with involvement of 492 school children of Dong Hoi and Thuy Lam primary schools of Dong Anh district, Hanoi city from November, 2011 to April, 2012. The results show that: the average of height and weight of school children increased gradually by age groups. Physical development of both boys and girls was similar. Height increased with speed of 5,08 cm/year in boys and 5,4 cm/year in girls. Weight increase with speed of 2.2 kg/year in boys and 3,0 kg/year in girls. Weight and height of school children in this two primary school were close to NCHS Reference. Prevalence of overweight and obesity in school children was 10.2 percent as in the whole,and 12.5 percent in boys and 7.7 percent in girls in particularly.