Objective To understand the status of physical fitness of 3 to 6-year old-children in Soochow, and to analyze the test results to find problems, in order to provide more scientific basis for facilitating of physical fitness. Method A total of 4 341 children aged 3~6 were selected to conduct physical test according to random cluster sampling methods in 2017, and their shape-indexes, quality indexes were analyzed. Results The growth and development of body shape, physical fitness in preschool children in Soochow was in accordance with the basic rules. Totally 92.1% of the 3 to 6-year old children (boys: 90.2%, girls:94.2%) in Soochow achieved physical development standards, and showed the trend that strong in girls and weak in boys(P＜0.01). The age difference on physique index except sit and reach (SR) of 3 to 6-year-old children in Soochow was significant(P＜0.01).The height and body weight were significantly higher than those of female children at the same age. For physical quality, the upper body strength, the sinews of belly and agility of male children were better than those of female children(P＜0.05), but the flexibility ability were contrast(P＜0.05). The height and body weight were higher than the national averages(P＜0.01), but a lot of physique index were lower than the whole country slightly. There were no significant differences on height (P=0.1)and the ten-meter dash(P=0.59) between public and private kindergartens, but other physique index of children in private kindergartens were superior to that of children in public kindergartens(P＜0.01). Conclusions The physical fitness level of preschool children in Soochow is unsatisfying. Effective physical activity is suggested to be done with the consideration of their physical characteristics to improve physical fitness.