The rheological and morphological properties for the blends of polyvinyl chloride (PVC) and linear low density polyethylene (LLDPE) were investigated. The effect of shear rate, blend composition and chemical modification of the blends by chlorinated polyethylene (CPE) addition were studied and the results were compared with non compatibilised blends. A decrease in the melt viscosity is observed with increase of shear rate, indicating pseudoplastic behavior. The incorporation of CPE to the binary blend increases the melt viscosity. The morphology of the blends was modified by compatibilisation. The rheological and morphological variations could be related to the interfacial tension and the size of the dispersed phase particles.