Abstract: In order to study the effects of baicalin against Avian infectious bronchitis virus（IBV） QX strain in vitro, IBV was rejuvenated and propagated. Primary chicken embryonic kidney（CEK） cells were prepared, and the TCID₅₀ of CEK cells was determined by IBV. The maximum non-toxic concentration（MNTC） of baicalin on CEK cells was determined. On the basis of MNTC, the effective inhibition rate of different concentrations of baicalin on IBV was determined by CCK method, and the inhibition of different concentrations of baicalin on cytopathie effect（CPE） of CEK cells caused by IBV was observed. The effect of different concentrations of baicalin on the relative expression of IBV N gene was determined by qPCR. The results showed that IBV was successfully rejuvenated and propagated, and it was not contaminated by other viruses. The TCID₅₀ of CEK cells was 1 × 10^-4.75/0.1 mL, and the MNTC of baicalin on CEK cells was 9.75 mg/L. The effective inhibition rate of baicalin at this concentration on IBV was the highest, which was 64.03%, which could effectively reduce the CPE of IBV on CEK cells. Baicalin at each concentration could significantly reduce the relative expression of IBV N gene in CEK cells（P＜0.01）. The results indicated that the MNTC of baicalin on CEK cells was 9.75 mg/L, and the concentration of baicalin had a good anti-IBV QX strain effect in vitro.