The diffraction properties of reflection volume holographic gratings are studied when the gratings are illuminated by an ultrashort beam with arbitrary polarization state. The modified Kogelnik's theory of coupled waves combining the dispersion effect in the LiNbO3 crystal is used. The dependences of the diffracted intensity distribution and the total diffraction efficiency of the reflection volume grating on the polarization angle of the input ultrashort pulse are investigated. For different polarization angle, numerical results about diffraction properties of the reflection volume holographic gratings are given and compared with the transmitting volume holographic gratings.