Abstract: Newcastle disease of chicken, caused by newcastle disease virus, is a kind of acute and highly-contagious infectious disease with higher lethallty rate. Nowadays, comprehensive prevention and control measures with vaccine inoculation as main measures are commonly used in China, which could control large-scale prevalence of Newcastle disease to a great extent. Chicken colibacillosis is a kind of infectious disease that caused by Escherichia coli. Various kinds of E. coli are main bacteria in the intestines of many kinds of animals and their distribution is extremely broad. And its pathogenic rate was higher, and E. coli is often mixed with the infection of other diseases. The mixed infection cases of Newcastle disease of chicken and colibacillosis were diagnosed by pathological examination of dead chicken, laboratory examination and drug sensitivity test on the isolated strains. And some comprehensive prevention and control measures were proposed so as to provide useful references for preventing and controlling colibacillosis and newcastle disease.