Based on the scattering theory of electromagnetic wave, the electromagnetic scattering field generated by an anisotropic quasi-homogeneous medium is investigated. Then the analysis formulas for spectral density and spectral degree of coherence of the electromagnetic scattering field are derived. Simulation results show that when the scattering potential matrix of the anisotropic quasi-homogeneous medium is Gaussian-correlated, the normalized spectral density of the anisotropic medium is close to the average of the corresponding isotropic medium. But the weight of every component is not only different from each other but also changing as the scattering angle changes. The spectral degree of coherence of the anisotropic medium is greatly different from that of of its corresponding isotropic medium. The spectral degree of coherence of the anisotropic medium is oscillating as a function of the angle by three phases. And at some certain scattering angles, the spectral degree of coherence of the anisotropic medium is nearly the same as that of the corresponding isotropic medium.