Objective：To summarize the clinical characteristics and to do etiological diagnosis for one confirmed case of plastic bronchitis. Methods：One child of more than 5 years old was enrolled. Clinical manifestations were fever，cough，gasp，anhelation and progressive difficulty of breath. Thoracic CT showed that the left lung had large parts of consolidation，possibly being pulmonary atelectasis. Bronchoscopy and lavage were conducted and the ingrown foreign body in the air passage being taken out. The child was diagnosed as plastic bronchitis. Bronchoalveolar lavage fluid of the sick child was taken out for detecting 16 kinds of respiratory viruses. Results：Detecting results of 16 kinds of respiratory viruses indicated that the sick child was influenza A virus positive，and the nucleoprotein sequencing of the further amplified virus was clarified as H3N2. At the same time，human bocavirus（HBoV） were found out and the number of virus copy was 3×105 copies/ml. The child was discharged from the hospital after the endogenous foreign matter being taken out. Conclusion：As a pediatric intensive case，plastic bronchitis can be clearly diagnosed by bronchoscopy and removing endogenous foreign body through lavage，which is essential for the effective treatment. The patient’s bronchoalveolar lavage etiological diagnosis remind us of mixed infection of human influenza viruses and HBoV，which is worthy of attention.