The four potential energy surfaces (PESs) associated, respectively to 1A′, 3A′, 1A″ and 3A" states correlating to the interacting CH(X2Π) + H(2S)system, were determined using the aug-cc-pVQZ basis set, and multireference internally contracted configuration-interaction (MRCI) calculation method including the Davidson correction. The CH bond length was fixed at the equilibrium value of the X2Π ground state. The PES of the A' state considerably differs from that of the A" state. The ab initio calculated interaction energies of the and PESs for each spin multiplicity were fitted analytically on the basis of Legendre polynomials.