The orientation-dependent transition matrix elements were evaluated for the energy transfer reaction CF3H + Ar(P-3) --> CF3* + Ar + H by ab initio SCF calculations. The elements were calculated as a function of the distance of the reactants. The results show that the collision along the symmetry axis of CF3H is preferable to produce the excited CF3H in the B or C state. The E state of CF3H, on the other hand, is preferably generated by the sideways attack. For heads and tails orientation, CASSCF wave functions were also employed for obtaining the electronic coupling. These calculations strongly support the previous results given by electron density analysis and also suggest that the electron exchange process at the second potential crossing point is dominant for the stereoanisotropy experimentally given. We discuss the dominant factors that determine the orientation effect in the title reaction.