AIM:To diagnose a patient with clinical symptoms of fever,cough and asthma.ME- THODS:The sputum of the patient was subjected to microscopic examination,and the clini- cal pictures of the patientwas analysed.RESULTS:The red blood- like substance in the spu- tum was preliminarily defined as parasitic nematodes.Species identification indicated that they were a pair of Mammomonogamus laryngeusadult worms in copulation. The patient had obvious signs and symptoms of respiratory tract infection and eosinophilia of peripheral blood. Detection of the worms or eggs is the main base for diagnosis. CONCLUSION:It is the first record of human Mammomonogamus laryngeus infection in China.