Objective To investigate the levels of vitamin D in the young children aged 0～3 years old and relationship with genders,ages and seasons. Method The serum levels of 25(OH)D in 2 381 children aged 0～3 years old were detected by electrochemiluminescence. Results Among 2 381 cases,the serum levels of 25(OH)D were (36.73±18.75)ng/ml,in which 8 cases(0.34%) were severe deficiency; 174 cases(7.31%) were deficiency;149 cases(6.55%) were insufficiency;2 026 cases(85.09%) were sufficiency; 24 cases(1.01%) were excess.There was no statistical difference between gender groups(P＞0.05).The serum 25(OH)D levels in the infants aged 0~1 year old were much lower than those of the children aged 1～3 years old group.There was statistical difference between 0~1 year old group and 1~3 years old group (P＜0.05).The serum 25(OH)D levels reached the highest in winter and the lowest in spring. Conclusions The level of serum 25(OH)D is great in the children aged 0～3 years old in Shenyang area.Supplementation of vitamin D should pay attention to scientific and reasonable,avoid VitD deficiency or excess,and even intoxication.