The study was carried out to define and evaluate the sensitivity of E.coli strains isolated from poultry to common antibiotics used in the field in order to limit the appearance of multi-antibiotic-resistant strains. Then after applying the bacterial or germinal and conformational biochemical tests by using intropolory techniques and quick agglutination tests. Existence of E.coli was diagnosed in 470 out of 600 hens suffering clear respiratory symptoms (78.33%). A number of 1060 isolates of E.coli had been taken from internal viscera, namely hearts, lungs, livers, spleens, tracheas. The latter contributed the highest percentage (86.15%) of the total number of isolates. Moreover, five patterns of pathogenic serum of E.coli (O1,O6,O8,O15,O78) were identified in (42.55%) of the isolates. The research results demonstrated that (100%) of all tested isolates were resistant to certain antibiotics (Penicillin, Ampicyllin, Tetracycline and Erythromycin) where 95.7 % and 91.4 % of the isolates were resistant to Kanamycin and Neomycin, respectively. On the other hand, (69.4%) of the isolates were found to be sensitive to Colistin, while sensitivity to Streptomycin, Trimethoprim and Chloramphenycol was between (36.2% - 27.6%). Finally speaking, in this study, E.coli strains were found to exhibit 24 resistance patterns to 11 different types of antibiotics.