In most of mountainous area, particularly in France, the dominant weathering process lies in cracks propagation due to freezingthawing. To predict this risk in rock masses, it is necessary to know the stresses developed in freeze-thaw cycles in natural fractures. A reproduction of this phenomenon has been carried out on artificially notched specimens of different limestones. During these experiments generated stresses were assessed along the crack inner walls. The deduced stress profiles show a timedependant maximum value, which moves in-depth in the notch. The limit reached by this stress in this process depends on intrinsic properties of the material. A simple model for this evolution has been established. The generated stress by freezingthawing in a crack comes from a coupling between thermal propagation, water phase shift and water flow in the notch and in the porous rock matrix. An analytical assessment of the stress intensity factor at the crack bottom was made by using the model established for the stress in the crack. It confirms the possibility to initiate a rupture according to the principles of linear failure mechanics. This study gives encouraging results, which could be used to establish a predictive model for the failure of a rock mass subject to freezing-thawing cycles.