Abstract: OBJECTIVE To analyze the changes of peripheral blood lymphocyte and atypical lymphocyte in children with respiratory tract infection infected by EB virus(EBV), and their correlation with EBV-DNA load. METHODS A total of 624 cases of children patients diagnosed with respiratory tract infection and 100 health control cases were collected from Mar. 2015 to Jun. 2016 in Chenzhou First People's Hospital. EB-DNA load in peripheral blood was detected by real-time fluorescence quantitative PCR, and the whole blood cell analyzer was used for routine blood test and the results of lymphocyte test were analyzed statistically. At the same time, peripheral blood atypical lymphocytes were artificially examined and the percentage was calculated. RESULTS None EBV-DNA was detected in control group, and the positive rate of EBV-DNA in respiratory tract infection group was 39.26% (245/624). The average EBV-DNA viral load of EBV-DNA positive samples was (3.56±0.68)log IU/ml. The EBV-DNA positive rate of children of 1~3 years old was higher than that of <1 year old and> 3 years old, and the positive rate of EBV-DNA in children with respiratory tract infection with different ages was significant (P<0.05). The percentages of lymphocyte and lymphocyte in the EBV-DNA positive group of children with respiratory tract infection were significantly higher than those in the EBV-DNA negative group and control group(P<0.001). CONCLUSION The percentages of lymphocyte and atypical lymphocytes were increased in children patients with respiratory tract infection infected by EBV, and positively related to EBV load, which can be regarded as an early assistant diagnostic indicator of respiratory tract infection with EBV and can also be applied to the basic level hospitals.