Abstract: Objective To provide the scientific basis for the CT scan in the diagnosis and differential diagnosis of pediatric tuberculosis (TB).Methods Retrospective analysis was applied by collecting CT scan data of 60 1 month-12 years old patients diagnosed as pulmonary TB (TB group) and of 72 1-12 years old patients diagnosed as pulmonary infectious diseases (including: 42 cases of the bacterial pneumonia, 20 cases of mycoplasma pneumonia, 10 cases of fungal pneumonia) (pneumonia group) from October 2009 to October 2014 in Guangzhou Chest Hospital. The incidence、anatomical sites (mediastinal, pulmonary hilar, axillary) distribution, density of CT scan and CT enhancement characteristic of lymphadenectasis were described by percentage composition. The significance of difference was analyzed and compared by Chi-square test. P<0.05 was considered statistically significant.Results 98.33% (59/60) patients of the TB group showed lymphadenectasis in CT scan, which was significantly higher than that of the pneumonia group (41.67%, 30/72) (χ²=47.85, P<0.05). In terms of anatomical site, 90.00% (54/60), 61.67% (37/60) and 48.33%(29/60) TB patients had lymphadenectasis shown in mediastinal, pulmonary hilar and axillary respectively, which were significantly higher than those of the pneumonia group [(22.22%, 16/72,χ²=60.36, P<0.05) (12.50%, 9/72,χ²=34.85, P<0.05) and (15.28%, 16/72,χ²=16.93, P<0.05)]. In terms of CT scan density, 52.54% (31/59), 42.37% (25/59) and 5.08% (3/59) of TB patients showed uniform density, calcification and necrosis, and 80.00% (24/30), 16.67% (5/30) and 3.33% (1/30) for the pneumonia group. The percentage of uniform density in pneumonia group was significantly higher than TB group χ²=6.35, P<0.05). The image of calcification was on the contrary (χ²=10.47, P<0.05). In the CT enhancement scan of 8 cases of TB group, the rates of uniform and uneven enhancement were 12.50% (1/8) and 87.50% (7/8). While 83.33%(10/12) and 16.67 (2/12) were shown in 12 cases of the pneumonia group.Conclusion The application of anatomical sites, density of CT scan, CT enhancement characteristic of lymphade-nectasis can help the diagnosis and differential diagnosis of pediatric tuberculosis.