The anisotropic conical diffraction generated by two extraordinary polarized beams with doped KNSBN crystals is reported. An anisotropic diffraction pattern with three diffraction cones has been observed for the first time. And the mechanism of photorefractive four wave mixing involved the incident beams and forward scattered beams satisfying the phase matching condition is proposed. For the experimental geometry in which the two beams incident on the sample symmetrically, we presented the dependence of the diffraction cones on the incident angles. The theoretical analysis agrees well with the experimental results.