Objective To study the correlation between blood zinc level and severity of rotavirus (RV) gastroenteritis (RVGE) by measuring whole blood zinc level in children with RVGE. Methods One-hundred-and-sixty-eight (168) children with RVGE in Fengxian District Central Hospital of Shanghai from October 2018 to December 2020 were selected as the RV group, and were divided into RV zinc deficiency group and RV normal zinc group, based on their blood zinc levels. The two groups were divided further into RV zinc deficiency treatment group, RV zinc deficiency control group, RV zinc normal treatment group and RV zinc normal control group. There were 124 healthy children who came to the hospital for physical examination in the same period were selected as the healthy control group. The whole blood zinc level of each group was detected by atomic absorption spectrometer. Results The whole blood zinc of RV group (62. 81± 10.92 μmol/L) was significantly lower than that of the healthy control group (71.31±7.74 μmol/L.) The proportion of zinc deficiency in RV group was higher than that in the healthy control group (P<0.05); The whole blood zinc level in the mild group of children with RVGE was (66.1± 10.6 μmol/L), which was higher than that of the moderate group (61.2±10.9 μmol/L) and the severe group (56.0±5.1 μmol/L), with statistically significant differences (P<0.05). The differences in severity of disease typing, proportion of dehydration, and number of stools between the RV zinc deficiency group and the RV zinc normal group were statistically significant (P<0.05). The disease course of the RV zinc deficiency control group was longer than that of the RV zinc deficiency treatment group, the RV zinc normal treatment group and the RV zinc normal control group, the difference was statistically significant (all P<0.05). Conclusion The level of whole blood zinc in children with RVGE decreased significantly, and the incidence of zinc deficiency was higher than that in healthy children. There was a correlation between the level of zinc and the severity of RVGE. Zinc supplementation was effective in the treatment of zinc deficiency children with RVGE..