Rosin-maleic anhydride adduct (RMA) was synthesized from rosin and maleic anhydride. The polyamideimides have been obtained by the direct polycondensation reaction of the adduct with various aromatic diamines. The reaction was catalyzed by triphenylphosphite in NMP_pyridin solvent mixture containing lithium chloride. We varied the catalyst concentration, compositons of solvent mixture and LiCl contents to investigate optimum reaction conditions. The polymers were characterized by infrared, elemental analysis, X -ray diffractometry and inherent viscosity measurement. The viscosity of polymers ranges from 0.16 to 0.51 dι/g; the highest viscosity was obtained from the polymer prepared by reacting RMA with 4,4''-diaminodiphenylmethane. The polymers were either amorphous or poorly crystalline and soluble only in highly polar aprotic solvents. The results of thermal analysis showed that the polymers had good thermal stability with the initial decomposition temperature ranging from 366℃ to 406℃. The polyamideimide obtained from RMA and 3,3''-dimethylbenzidine had the highest decomposition temperature. According to DSC analysis of polymers, the glass transition temperature was over 260℃ and the melting point couldn''t be detected.