OBJECTIVE: To investigate the clinical characteristics and management of the first confirmed imported case of influenza A (H1N1) infection in mainland China. METHODS: The description of the clinical manifestations, clinical management, infection preventing and controlling strategies were reviewed. RESULTS: The 30-years old male patient came back from U.S.A. and with mild influenza-like symptoms developed. He had had a close contact history with a patient with "common cold" 4 d before onset of illness. Influenza A (H1N1) virus newly confirmed in North American was detected in the throat swab samples taken from this patient by real-time PCR and sequencing comparison. His symptoms ameliorated soon after administration of oseltamivir. The temperature was back to normal on the second day with oseltamivir. Nucleic acid of Influenza A (H1N1) virus was undetectable after 3 d with oseltamivir management. The patient was discharged on the 7 d after hospitalization. CONCLUSIONS: The clinical presentations of this imported case with Influenza A(H1N1) infection suggest that A(H1N1) infection manifests as flu-like symptoms in the healthy young people with a mild clinical course and a good prognosis. Early identification, early diagnosis and intervention with oseltamivir might be an effective clinical strategies for management of this emerging infectious disease.