Abstract: ObjectiveThe clinical prevention and treatment effects of Jiebai granule(trade name Lekangning) on avian infectious bronchitis(IB) were evaluated, in order to provide a new idea for using traditional Chinese medicine to prevent and cure IB. MethodA total of 130 1-day-old non-immunized chicks were randomly divided into 6 group(Jiebai granule prevention group, treatment group, drug control group, vaccine group, model control group and healthy control group). Thirty chicks were in vaccine group and twenty chicks in other groups. Except for healthy control group, the chicks in oth-er groups were challenged oculonasally with avian infectious bronchitis virus(IBV) M41 strain at 15-day old, and Jiebai granule was added into drinking water before 5 days(at 10-day old) of challenge in prevention group. In Jiebai granule treatment group and Yinhuang oral solution treatment control group, Jiebai granule and Yinhuang oral solution were added into drinking water, respectively when more than half of the chicks were sick. In vaccine group, chicks were vaccinated with H120 vaccine at 7-day old, and partial vaccinated chicks drank water with Jiebai granule, other vaccinated chicks were treated without Jiebai granule. After IBV infection, the incidence, protection rate, cure rate and respiratory symptom scores of each group were counted. The weight gain and immune organ index, the levels of IBV antibodies in serum were analyzed. ResultAt 8 d after being infected with IBV(at 23-day old), the protection rate was 50.00% in prevention group and 45.00% in vaccine without drug group. The cure rates were 66.67%, and 58.82% in treatment group and treat-ment without drug group, respectively. The clinical symptoms score was the lowest in vaccine without drug group, followed by prevention and treatment groups. The spleen in treatment group were significantly higher than those in other groups at the 12 d after drug withdrawal(at 36-day old)(P<0.05, the same below). The antibody titers of prevention and treat-ment group were reach the peak at the 14 d post infection(dpi)(at 29-day old), and still kept at high level at 21 dpi(at 36-day old). The antibody titer of the vaccine with drug group was significantly higher than that of vaccine without drug group. ConclusionThe Jiebai granule can reduce the incidence of IB and cure the sick chickens. At the same time, Jiebai granule can enhance immunity by promoting the development of spleen and other immune organs, promoting anti-body production and increasing the maintenance time of antibody. The Jiebai granule has a better clinical prevention and treatment effect on IB.