Background: Children vulnerable to Human cytomegalovirus ( HCMV ) infection, most of them are recessive infection, easy to lead to missed diagnosis. However, missing early diagnosis and treatment may have adverse consequences for the child. Therefore, the purpose of this study was to evaluate the hematological parameters in HCMV-infected infants or children less than 6 years. Method：A retrospective analysis of 223 children aged 0-6 years who had accepted urine HCMV-DNA testing in Luohu People’s Hospital. The children were divided into 0 day-21 days, 22 days-6 months, 7 months-11 months, 12 months-23 months, and 2 years-6 years groups according to their age when they were tested, and total white blood cell count (WBC), lymphocyte percentage (L%), lymphocyte count (LYM), alanine transaminsase (ALT), aspartate transaminase (AST), γ-glutamy1 transferase (GGT), urea nitrogen (UREA), and creatinine (CREA) of different age groups were compared. Results: The L% and LYM of HCMV-infected children aged 0d-6y were significantly higher than those of the control group ( P<0.05); The ALT and GGT of HCMV-infected children aged 0-12m and AST of HCMV-infected children aged 0d-2y were significantly higher than control group ( P<0.05), but this difference did not show up among older children ( P<0.05); Compared with control group, there was no significant difference in UREA and CREA of HCMV-infected children aged 0d-6y ( P>0.05). In addition, we found that GGT was highest in HCMV-infected children aged 0-21d and decreased with the increase of age. Conclusion：HCMV infection can increase lymphocytes in the peripheral blood of children from 0 to 6 years old, and cause more serious hepatobiliary injury to younger children. However, renal damage caused by HCMV is rare in childhood.