Objective To investigate the effect of some clinical factors on the morbidity of Post infection Cough ( PIC ). Methods By means of retrospective study, some clinical factors including gender, age(≥50 years old), fever or cough appeared in initial stage of upper respiratory infection, chronic disease , medicine therapy in initial stage（≤48h） of upper respiratory infection were analyzed to determine which one is the risk factor for Post infection Cough. Results Gender, age(≥50 years old), fever or cough, chronic disease do not affect the morbidity of PIC . Deficiency of medicine therapy in initial stage（≤48h）of upper respiratory infection is an independent risk factor for PIC（OR=200 , P<0.001）. Conclusion Deficiency of medicine therapy in initial stage（≤48h）of upper respiratory infection can increase significantly the morbidity of PIC, which usually lead to an increased burden on patients and hospitals.