Abstract: We chose 420 AA kero-chicken of uniform size and divide them into 14 groups (30 chicken for each group) randomly. We used seven groups for the prophylactic trial, while the other seven groups for the therapeutic test. The results indicated that there was no significant difference between groups of the investigational drug of high and moderate dose（P>0.05）; while there was a significant difference compared with the investigation drug of low dose and the FM control group（P<0.05）; there was a remarkable difference compared with astragalan control group（P<0.01）. The results demonstrated that the high and moderate dose of Western and Chinese medicines could prevent and cure the colibacillosis of chicken effectively.

Key words: Western and Chinese medicines; AA kero-chicken; colibacillus; therapeutic effect test