Nanofiltration(NF45) and reverse osmosis membrane(HR98PP) separation treatment of dyestuff wastewater was carried out in order to separate relativley pure water from synthetic dyestuff wastewater, which consists of reactive dye, acid dye, basic dye, direct dye, and disperse dye. The experiments were performed by using the plate and frame membrane module. Permeate flux of two membranes increased as temperature increased due to segmental movement of polymer of the membrane and the rejection rate of dyestuff was decreased gradually. It was found that the rejection rate was about 95% in the nanofiltration while the reverse osmosis membrane showed a high rejection rate of 99% under all temperature and pressures conditions.