The aim of the study was to investigate the intravital lung parenchyma lesions follow-up in severe forms of experimental influenza infection by CT. An experimental study was carried out on 40 male C57black/6 mice weighing 16-18 g. Animals were divided into two groups: 1) uninfected mice - n = 10; 2) infected mice - n = 30 (infected intranasally with influenza virus A/PuertoRico/8/34 (H1N1), infectious dose 4.4 lg TID50/animal). The severity of infection was assessed according to the following criteria: daily control of the animals’ body weight; intravital lungs CT; lungs biometric and morphological examination. CT was performed in 5 randomly selected animals from the infection group at the first, third and fifth day after infection.