EPR spectra of V4+-doped single crystal (V4+/KTP) were observed in X band at room temperature. The analysis on the spectra shows that the V4+ ions may occupy two kinds of crystallographically diffrent sites, each kind of sites contains four magnetically nonequivalent but crystallographically equivalent sites. The angular varitions of EPR hyperfine lines were measured with the external magnetic field in three mutually perpendicular planes. The principal values and direction cosines of the principal axes of the g and A tensors, were computed by a least-squares fitting procedure. These main results reveal that the V enters the lattice to substitute for the Ti ion of KTP to form V site with a tetragonally distorted octahetral symmetry. The orientations of all eight Ti ion sites substituted in an unit cell of KTP have been determined.