In this study, we report the effect of different additives added with amine reactants on aliphaticaromatic and aromatic-aromatic types thin-film composite (TFC) polyamide reverse osmosis membranes performance that are prepared by in-situ interfacial polymerization. Aliphatic-aromatic polyamide membranes are prepared using polyethylene imine and 1, 3-benzene dicarbonyl chloride whereas aromatic-aromatic polyamide membranes are prepared using 1,4-phenylene diamine and 1,3,5-benzene tricarbonyl chloride. Additives used with amine reactants for TFC membrane preparation are (a) acid acceptors like sodium hydroxide, trisodium phosphate and triethyl amine, (b) aqueous soluble organic additives like isopropyl alcohol and dimethyl sulfoxide and (c) inorganic salts like feme chloride and copper sulfate. The performances of prepared composite membranes are evaluated with respect to separation characteristics of sodium chloride and magnesium sulfate solutes. It is found that presence of inorganic and organic acid acceptors in amine solution has different impacts on aliphatic-aromatic and aromatic-aromatic type polyamide composite membrane performances. Change in membrane performance is more for aromaticaromatic polyamide in presence of aqueous soluble organic additives but it is more for aliphaticaromatic polyamide in presence of inorganic salt additives in amine solution. © MD Publications Pvt. Ltd.