Since it was discovered in 7 March 2013,the index case of human avian influenza A (H7N9) in Hangzhou,a total of 61 confirmed cases of human avian influenza A (H7N9) including 20 deaths (32.79%) and 41cases of cure (67.21%) were reported in Hangzhou as of 30 June 2014.Among the 61 cases,the onset of the H7N9 cases was grouped mainly in January 2014 (27 cases) or April 2013 (27 cases) ,who make up 88.52 percent of the total.Among them,males were 46 cases (75.41%) and females were 15 cases (24.59%) ,proportion of males to females was 3.07 to 1,proportion of urban to rural was also 3.07 to 1,and proportion of ≥60 years to <60 years was 0.97 to 1 (30∶31) .The occupation distribution of the H7N9 cases was based on retired people,farmers,workers and self-employed persons (51 cases) ,who make up 83.61 percent of the total.Among them,59.02% (36/61) were education degree of primary school and illiteracy.Among the 61 cases,60.66% (37/61) were past history of chronic disease,24.59% (15/61) were history of surgery,55.74% (34/61) were of recent history exposed to live poultry,and 81.97% (50/61) were of recent history exposed to live poultry in markets.Of all 61 cases,they werent history of flu vaccination.To investigate the possible origins of the H7N9 viruses causing these human infections,we collected 159 samples in 2013,including cloacal and tracheal swabs of poultry from live poultry markets and poultry farms in Hangzhou,eighty samples (50.31%) were positive for the H7N9 influenza virus.Among the 159 samples,the positive rate of H7N9 nucleic acid (64.44%) for samples of cases-related were significantly more than samples of the irrelevant cases (31.88%) [x2 =16.56,P<0.05,OR=3.87 (95%CI:2.00-7.51) ].We collected 644 samples in 2014,including cloacal and tracheal swabs of poultry from live poultry markets and poultry farms in Hangzhou,159 samples (24.69%) were positive for the H7N9 influenza virus.Among the 644 samples,the positive rate of H7N9 nucleic acid (31.34%) for samples of cases-related were more than samples of the irrelevant cases (22.94%) [x2=4.03, P<0.05, OR=1.53 (95%CI:1.01-2.33) ].A total of 803 samples were collected between 2013 and 2014,including cloacal and tracheal swabs of poultry from live poultry markets and poultry farms in Hangzhou,239 samples (29.76%) were positive for the H7N9 influenza virus.Among the 803 samples,the positive rate of H7N9 nucleic acid (44.64%) for samples of cases-related were significantly more than samples of the irrelevant cases (24.01%) [x2=32.90,P<0.05,OR=2.55 (95%CI:1.85-3.53) ].A retrospective study was conducted among patients with avian influenza A (H7N9) in Hangzhou between 1 March 2013 and 2 March 2014.Patients were classified into cure group and death group according to disease outcomes.Demographic,clinical and epidemiological data were collected and compared by descriptive statistics and univariate analysis,to explore risk factors for death in human avian influenza A (H7N9) cases.A total of 61 patients were included,among which 20 (32.79%) were fatal.Deaths attributed to human avian influenza A (H7N9) was three to one for ratio of men to women.In addition,average age of death patients was older than cured patients (t=1.97,P=0.05≤0.05) .In univariate analysis,elder than 60 years [x2 =5.16,P=0.02<0.05,OR= 3.65 (95%CI:1.19-11.13) ],less education (primary school or illiteracy) [x2=5.42,P=0.02 < 0.05,OR=4.20 (95%CI:1.24-14.00) ],chronic diseases[x2=4.67,P=0.03 < 0.05,OR= 3.81 (95%CI:1.12-12.69) ],bad hand washing after handling raw poultry [x2 =4.05,P=0.04 < 0.05,OR=4.67 (95%CI:1.04-11.56) ],CRP≥120mg/L[x2=4.04,P=0.04 < 0.05,OR=6.00 (95%CI:1.04-35.33) ],NE%of first exam (greater than normal result) [x2= 3.90,P=0.05≤0.05,OR=4.58 (95%CI: 1.01–34.22) ],and L%of first exam (lower than normal result) [x2 =7.12,P=0.01<0.05,OR=7.53 (95%CI:1.63-24.51) ].