Abstract: After being reared on ground for one week,150 broilers,healthy and temperate in size,were selected from 180 one-day-old AA chickens. Then they were inoculated with avian infectious bronchitis vaccine for the primary immunization,and randomly divided into five groups,with three duplicates in each group and 10 broilers in each duplicate. After five weeks post the immunization,the Chinese herbal medicines,honeysuckle,astragalus,and bupleurum,were respectively added to the drinking water of group 2,group 3,and group 4 in the proportion of 1 %; the drinking water of group 5 was added with the compound preparation,composed of honeysuckle,astragalus,and bupleurum; group 1 was taken as control,without any drug added in drinking water. At the 14th d and the 28th d post immunization,the sera were separated from blood collected from heart to detect HI antibody titer of the avian infectious bronchitis. As shown by the experimental results,the HI antibody titer of the avian infectious bronchitis and the indexes of immune organs were higher in most of broilers of the experimental group than in the control group. And the most significant effect appeared in group 5,added with compound preparation （containing honeysuckle,astragalus,and bupleurum）.