Based on the accurate expression of light intensity of nonparaxial vector beams at the transverse plane and the vectorial second order moment theory of light beam propagation，by applying rigorous vectorial diffraction theory of the angular spectrum representation，the nonparaxial propagation of any vectorial diffraction beam has been systemically investigated，the integral expressions of beam width，transversal divergence angle have been presented，and the divergent characteristic of the second order moment of nonparaxial vector beams has been demonstrated. The definitions of beam width，transversal divergence angle of non-paraxial vector beams and some related problems have been discussed.