Abstract： The theory proposed by P. Vogl ct al. is extended to the 3d-transition metal impurities doped GaAs1-xPx alloy system. For different compositions, i.e. different x, the acceptor levels, donor levels, local charges and spin-densities of different 3d impurities are predicted. The theory agrees well with the relevant experimental data and reveals their major chemical trends. The physical mechanisms which are responsible for the variation trends of theoretical and experimental results are also discussed.