Objective To understand the nutritional status of 25-hydroxy vitamin D[25-(OH)D] and the relationships with age and season in 0~6 years old children in Nanhai district of Foshan city. Methods A total of 5 017 children aged 0~6 years old for physical examination in Nanhai Maternal and Child Health Care Hospital in 2014,and venous blood samples were collected from subjects before breakfast in the morning.Their test results of 25-(OH)D were detected by the high efficiency liquid chromatography- tandom mass spectrometer. Results The average level of 25-(OH)D was 69.07 nmol/L in 5 017 children aged 0~6 years old in Nanhai District in 2014.The percentage of 25-(OH)D famine was 0.09%.The percentage of 25-(OH)D deficiency was 18.71%.The percentage of 25-(OH)D insufficient was 31.01%.The percentage of 25-(OH)D sufficient was 50.16%.The detection level decreased with age(P＜0.05).The detection level of summer and autumn was higher than that in spring and winter(P＜0.05). Conclusions The level of 25-(OH)D in children in Nanhai district is low.Vitamin D preparation can be supplement from the neonatal period until the child and adolescent stage.