Abstract: 　Objective　To investigate the clinical features of Escherichia coli pneumonia, the positive rate of extend-spectrum β-lactamase (ESBLs) produced by Escherichia coli and antimicrobial resistance of Escherichia coli. Methods Three hundred and thirty-six infants with Escherichia coli pneumonia were divided into community acquired infection group and hospital acquired infection group from Jun 2003 to Jun 2013. The clinical data of those patients were collected and analyzed. The ESBLs were examined, and drug susceptibility results were analyzed. Results Infants under 6 months had higher infective rate of Escherichia coli. The Escherichia coli pneumonia had similar clinical manifestations as Gram negative bacterial pneumonia. ESBLs were found in most strains (58.3%, 196/336), positive rate of ESBLs of hospital acquired infection group (84.00%) was higher than that of community acquired infection group (50.96%) ( χ²=26.17, P<0.05). There was no difference of ESBLs positive rate between the community acquired infection groups during Jun 2003-May 2008 and those during Jun 2008-Jun 2013 (χ²=0.30, P>0.05). The ESBLs positive rate of hospital acquired infection group was significantly increased from 76.74% (Jun 2003-May 2008) to 93.75% (Jun 2008-Jun 2013) (χ²=3.95, P<0.05). The most sensitive antibiotic was carbapenem. Conclusions Escherichia coli pneumonia mainly occurs in infants, usually with severe clinical situations and more persistent. The hospital acquired infection is the high risk factor of acquiring ESBLs. Antibiotics should be prescribed depending on community acquired infection or hospital acquired infection.