Abstract: Determination of biochemical characteristics, O-antigen identification, drug sensitivity test were studied on the 132 pathogenic E.coli that isolated from the typical periheptosis of chickens in Handan city , Xingtai city, Shijiazhuang city, Hengshui city, Cangzhou city in Hebei Province between March 2003 and April 2008. The results show that 132 isolates are in correspondence with biochemical characteristics of pathogenic E. coli. We have identified 103 strains which belong to 25 O-antigen types with 55 kinds of single-factor positive serum and the rate of the isolated strains was 78.03% (103/132).The drug sensitivity test used by O1, O21, O65, O78, O93 serotype of 15 strains (each serotype selected three different sources of strain) that confirmed most strains high sensitivity to amikacin, mid-sensitivity to ceftriaxone, and sulfa-metronidazole to tolerance.