Abstract: Objective The study was conducted to analyze the surveillance results ot unexplained pneumonia cases in Zhejiang from 2005 to 2006 for the formulation of strategies for the prevention and control of SARS and Human avian influenza.Methods Statistical analysis were performed on the surveillance data of unexplained pneumonia in Zhejiang Province from 2005 to 2006.Results 29 cases of unexplained pneumonia were reported from 2005 to 2006 in Zhejiang.Nine mistaken cases and three cooperatively investigated cases in other provinces excluded,there were actually 17 reported cases,one case of which was diagnosed high-pathogenic human avian influenza.The reported ratio of male to female was 1.43:1.Children and aged people were mostly affected.82.35% of unexplained pneumonia cases were reported in winter and spring.Farmers were the major affected occupation.14 cases were found with influenza-like symptoms when sent to the hospital,accounting for 82.35%. Conclusion Influenza-like symptoms were clinically significant for the diagnosis of unexplained pneumonia.Clinical diagnoses and reports of unexplained pneumonia cases should be normalized to fa- vor the early discovery of cases of SARS or human avian influenza.