In the current research polyvinylchloride-based nanocomposite nanofiltration membranes were prepared by using of sodium dodecyl sulfate (SDS) as additive, aluminum oxide (Al2O3) nanoparticles as inorganic filler and dimethylacetamide (DMAC)/tetrahydrofuran (THF) as solvents via phase inversion method. The effect of solvents ratio (DMAC to THF), SDS concentration and Al2O3 nanoparticle concentration in the casting solution on membrane physicochemical properties was studied. The flux, selectivity and water content measurements and also scanning electron microscope analysis were carried out for the membrane characterization. The increase of THF concentration in the casting solution led to decrease of membrane flux and increase of salt rejection. Additionally, flux was reduced, and rejection was enhanced by utilizing of SDS in the casting solution significantly. Furthermore, membrane flux was improved initially and then declined by increase of Al2O3 nanoparticle content ratio in membrane matrix. This was followed by nearly constant trend of rejection by increase of nanoparticle concentration. The optimum concentrations of used SDS and Al2O3 nanoparticles and solvent (DMAC:THF) ratio were found 0.45 %wt, 0.05 %wt and (85:15) (V/V) respectively.