In this paper, we have found the conformastat flat solution in the theory of gravita-tion by eondering the vector graviton field and the metric field. We introduce Hu-Ning's expression into this theory, then it appears also as the conservative expression of energy-monentum. For the gravitational field of singular centralized mass, it can be shown, as in GR, that the gravitational mass and the inertial mass are equal. But Einstein's principle of equivalence doesn't hold in this theory. When n