TBKl gene plays an important role in natural antibacterial immunity. In order to study the expression level of this gene in antibacterial immunity of grass carp (Ctenopharyngodon idella), this study designed two pairs of specific primers according to the reported TBK1 gene (ciTBK1) sequence of grass carp. A quantitative realtime PCR (qRT PCR) method was established based on ciTBK1 and 18S rRNA double standard curves. The results showed that the standard curve had a good linear relationship between Ct values and the logarithm of template concentration, with an excellent correlation coefficient (R²＞0.99). The qRT PCR method could detect ciTBKl gene quantitatively with a sensitivity of 50 copies/μL and the intra and inter group variation coefficients were less than 5%. The qRT PCR method has good specificity, sensitivity and repeatability. [Chinese Fishery Quality and Standards,2022,12(6):09-14]