PP/TPS blends were prepared using a single screw extruder, rheological tests showed that PP/TPS blends were pseudoplastic and exhibited the shear-thinning behavior where the viscosity decreased with increasing shear rate and the flow behavior of the blends is more sensitive to temperature compared with PP. Also, it was found that the true viscosity of the blend at 10% of TPS20 indicates negative deviation blends (NDBs) while above 10% it indicates a positive deviation blends (PDBs). Mechanical tests showed that stress at break of the blends decreases with increasing TPS content, whereas it increases slightly with increasing glycerol content. Also, it was found that the strain at break decreases with increasing both TPS and glycerol content.