Objective To understand the status of vitamin D(VD) deficiency of children in Dongguan and the relationship between vitamin D deficiency and platelet parameters. Methods A retrospective survey was used, and 2 337 children aged 6 months-14 years were selected from the Department of Child Health Care.Blood routine and serum 25-hydroxyvitamin D[25-(OH)D] test have been done to analysis the incidence of vitamin D deficiency and its correlation with platelet parameters. Results The deficiency rate and insufficient rate of VD in children was 14.46% and 25.03%,respeltirely. VD deficiency rate and insufficient rate were highest in school-age group,followed by preschool group and infant group,The insufficient rate of VD in boys was lower than that in girls(P<0.05),but there was no significant difference on VD deficiency rate between different genders.With the increasing of age,25-(OH)D level and platelet(PLT) count decreased,mean platelet volume(MPV) and platelet distribution width(PDW) increased,and the difference was statistically significant(P<0.05).There were no statistically significant differences on 25-(OH)D level and platelet parameters between different genders(P>0.05);There were statistically differences on PLT count,MPV and PDWamong VD deficiency group,VD insufficient were and normal group,while the difference between VD deficiency group and VD insufficient group was not statistically significant(P>0.05) The results of multi-classification Logistic regression analysis showed that VD deficiency and insufficient were correlated with age increasing,MPV increasing and PDW decreasing. Conclusions The deficiency rate and insufficient rate of VD in children are high.With the increasing of age,the rate of VD deficiency increases gradually,so the intervention needs to be strengthened.In addition,the deficiency of VD may be correlated with the increase of MPV and the decrease of PDW.