In this work, the interaction, crystallization and morphology of membranes derived from polyamides/poly (vinylalcohol) (PA/PVA, PA: PA66, PA69, PA610 and PA612) blend, materials are studied at various weight fractions and various crystallization temperatures. The experimental work includes differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), polarized optical microscopy (POM) and scanning electron microscopy (SEM). The equilibrium melting temperatures of polyamides in the blends are obtained using Hoffman-Weeks plots, and the interaction parameters are calculated using the Nishi-Wang equation, which is based on the Flory-Huggins theory. The values of the Flory-Huggins interaction parameters chi(12) are negative. Significant upward shifts of V-NH are observed with increasing volume fraction of PVA. The morphology of membranes is impressively complex, diverse, and irregular. All compositions that show nodular morphology are in the mu m-scale and the size of the nodules increases with increasing PA6 content. Large void cavities are observed in the substructure for the lower polymer concentrations.