A recent version of Statistical Associating Fluid Theory, namely SAFT2, coupled with the van der Waals and Platteeuw Model for the hydrate phase, is applied to represent the hydrate dissociation conditions for pure alkanes and their mixtures in systems Without inhibitors The proposed model is applied to both structure I and II hydrates at temperatures above and below the freezing point of water For binary and ternary alkane Mixtures; a. correction factor with Only One parameter is introduced to the model. The results indicate that, for these uninhibited systems; the proposed Model predicts the hydrate dissociation conditions well and captures the effect of concentration on the dissociation pressure well.