Objective To analyze the serum 25-hydroxy vitamin D[25(OH)D]levels and vitamin D nutri-tional status of 0-14 years old children in Hangzhou,and to provide scientific basis for the prevention of vita-min D deficiency.Methods A total of 26 225 healthy children aged 0 to 14 who were tested in Hangzhou Dian Medical Diagnosis Center from January 1,2021 to December 31,2023 were selected as the study objects.The 25(OH)D levels were detected by direct chemiluminescence method,and the 25(OH)D levels and vitamin D nutritional status of children with different genders,ages and seasons were analyzed and compared.Results The level of 25(OH)D in girls was slightly higher than that in boys,and the difference was statisti-cally significant(P＜0.05).With the increase of age,the level of 25(OH)D continued to decline,and the pro-portion of vitamin D deficiency and vitamin D insufficiency gradually increased.The level of 25(OH)D was the highest in children＜3 years old and the lowest in children 10-14 years old.There was statistical significance in the proportion of vitamin D nutritional status between boys and girls aged 10 to 14(P＜0.05).In the four seasons,children's 25(OH)D level is the highest in spring and the lowest in summer.The difference of 25(OH)D level and vitamin D nutritional status in different seasons was statistically significant(P＜0.05).The proportion of vitamin D deficiency and vitamin D insufficiency in winter was higher than that in other seasons,and the difference was statistically significant(P＜0.05).Conclusion The nutritional status of vitamin D in 0-14 year old children in Hangzhou is good,but the importance of vitamin D supplementation for children should not be ignored,and active publicity and education should be carried out to prevent vitamin D deficiency.