Objective The study aimed to explore the growth status of children under 3 years of age in Nankai district of Tianjin city,provide reference evidence for children's health care work of the local area.Methods Convenience sampling was used to collect physical examination records of children under 3 years old from Wangdingdi hospital in Nankai district of Tianjin city.The records of 2 880 children' physical examination data were collected.Results The median scores of weight for height (WHZ) of children of 6,9,12,18 months old were 0.74 (0.01,1.49),0.73 (0.08,1.38),0.58 (0.11,1.27),0.54 (0.14,1.22),while children of 3,24,36 months old were 0.29 (0.45,1.03),0.17 (0.61,0.95),0.22 (0.36,0.80),the difference between them had statistical significance,x2=21.71,P＜0.05.The median scores of height for age (HAZ) of children of 3,6,9,12,16 months old were 1.05 (0.33,1.76),1.09 (0.32,1.85),1.22 (0.41,2.02),1.00 (0.20,1.79),1.09 (0.19,1.99),while children of 18,24 months old were 0.79 (0.06,1.51),0.86 (0.15,1.56),the difference between them had statistical significance,x2=27.83,P＜0.05.The median scores of weight for age (WAZ) of children of 3,12,18,24,36 months old were 0.88 (0.29,1.46),0.96 (0.31,1.61),0.85(0.19,1.51),0.64 (0.04,1.23),0.91 (0.28,1.54),while children of 6,9 months old were 1.10 (0.43,1.76),1.09 (0.43,1.74),the difference between them had statistical significance,x2=36.95,P＜0.05.The prevalence of stunting,wasting and overweight were 0.3％ (10/2 880),0.8％ (22/2 880) and 9.3％ (267/2 880).The physical condition between premature and full term infants and post-mature infants had statistical significance,t=140.23,100.64,P＜0.05.Conclusions The growth and development status of children in Tianjin Nankai district under 3 years old was generally good,and there was no significant difference between boys and girls,however,overweight has been the most serious problem at present.Compared with full-term and post-mature infants,the physical condition of premature newborn was lower.