The influence of atomic internal state population on its translational motion in a quantized standing wave cavity field with spatial periodic structure is investigated. On the basis of atomic two photon resonance transition and with the aid of the atomic field dressed state, the Schrodinger equations satisfied by the atomic translational motion for two different atomic dressed internal states are built and their general relation for a spatial periodic cavity field is obtained. Under an appropriate approximation, the state vector of the whole system is derived and the study of the interaction between the atomic internal state and its translational dynamics is allowed. It is found that the distortion of the atomic translational motion wave packet is sensitive to its initial internal state population for a quantized standing wave cavity field at coherent state.