The temperature dependence of the critical resolved shear stress (CRSS) of molybdenum single crystal has been investigated. It was found that the logarithm value of CRSS varies linearly with the absolute temperature which is not in agreement with Cottrell-Bilby's relationship based on atmosphere locking. Assuming that a chemical exchange bond between the impurity and dangling atoms would be weakened with rise in temperature and using the Morse function, the experimental linear Inσ-T relationship could then be accounted for and a slope of the right order of magnitude established.