Abstract: OBJECTIVE To detect the level of serum C-reactive protein (CRP) in children with acute respiratory tract infections and evaluate the clinical diagnostic value. METHODS A total of 122 children with acute respiratory tract infections who were treated in hospitals from Sep 2014 to Sep 2015 were enrolled in the study and divided into the bacterial infection group with 58 cases and the viral infection group with 64 cases according to the pathogens causing the infections, meanwhile, 60 healthy children who received the physical examination were set as the control group.The white blood cell counts and serum CRP level were determined and compared among the three groups of children. RESULTS The level of serum CRP and abnormal rate of CRP were significantly higher in the bacterial infection group than in the viral infection group and the control group during the treatment(P＜0.05).The level of serum CRP and abnormal rate of CRP of the bacterial infection group were significantly lower after the treatment than before the treatment(P＜0.05). CONCLUSION The detection of serum CRP may facilitate the early identification and diagnosis of the acute respiratory tract infections in the children, the dynamic monitoring of change of the serum CRP level has certain clinical value, and it can be used as an important indicator for early diagnosis of the children with acute respiratory tract infections.