The membranes were prepared from the blend of NR-g-PVA and PAA. For grafting of PVA on NR, the grafting percentage (%GP) of PVA was found to increase almost linearly with the amount of added PVA but did not change as increased initiator concentration. The particle size measurement of NR-g-PVA by dynamic light scattering (DLS) showed a larger particle diameter compared to that of bared NR in which the particle size of NR-g-PVA increased with the %GP of PVA. For NR-g-PVA/PAA membranes, the degree of swelling increased with increasing of water concentration and PAA content in the membranes. The pervaporation dehydration of ethanol-water mixtures using NR-g-PVA/PAA membranes was performed. At low feed water content where the membrane swelling was less, increasing the amount of PAA in the membranes would enhance significantly the permeate flux and separation factor. Nevertheless at higher feed water content, the membranes were in the state of excessive swelling. Giving the enhancement of permeate flux but decrease of separation factor as increased PAA content. The highest separation factor can be achieved at 25 wt.% PAA content and 5 vol.% of feed water content with feed temperature at 30 oC. Furthermore, increasing feed temperature was found to enhance the permeate flux but deteriorating the separation factor.