OBJECTIVE: To study changes in the physical growth of preschool children aged 3 to 6 yeas in urban areas of Lanzhou from 2001 to 2010. METHODS: Stratified, randomized, cluster sampling was used to collect physical examination data on children from 35 private and public kindergartens located in different urban areas of Lanzhou in 2001, 2006, and 2010. Changes in physical growth were analyzed using body height, body weight and body mass index (BMI) as main indices. Growth retardation, underweight, overweight, emaciation and obesity were screened out using height for age (HAZ), weight for age (WAZ), and weight for height (WHZ) and changes from 2001 to 2010 were analyzed. RESULTS: Body height, body weight and BMI increased from 2001 to 2010 in children at different ages (P<0.05). Body height and weight increased with age, while BMI decreased with age. Mean values of HAZ, WAZ, and WHZ increased over time, showing that prevalence rates of underweight, growth retardation, and emaciation decreased from 2001 to 2010 while those of overweight and obesity increased. CONCLUSIONS: Changes in the physical growth of preschool children in urban areas of Lanzhou from 2001 to 2010 were obvious, with increases in body height and body weight. However, problems such as overweight and obesity emerged. In response, while malnutrition is being solved, attention should be paid to over-nutrition that has an adverse effect on physical growth.