Based on the 31 high redshift (𝑧 > 2) Flat Spectral Radio Quasars (FSRQs), which is from the second Fermi-LAT AGNs catalogue (2LAC), we studied the correlation between flux densities (𝐹R, 𝐹K, 𝐹𝛾) in the radio, infrared and 𝛾-ray wave bands. We found that there is a significant positive correlation between 𝐹𝛾 and 𝐹R, and a weak anticorrelation between 𝐹𝛾 and 𝐹K in the average state. For high redshift blazars, we argue that the seed photon of 𝛾-ray emission mainly comes from the jet itself and partially from the dusty torus.
