A series of polyester-imides was prepared from diacid (imide-diacid [M1-M4] or a mixture of imide-diacid and terephthalic acid [TPA]) and bisphenol A in the presence of diphenyl chlorophosphate (DPCP) and pyridine as a direct condensation agent. The inherent viscosities of homo- and copolyester-imides were in the range of 0.39-0.58 dL/g. Almost all these homo- and copolyester-imides were completely soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAC), dimethylformamide (DMF), and m-cresol. The thermal properties of homo- and copolyester-imides were examined by DSC and TGA. These copolyester-imides had glass transition temperatures in the range of 95-240 degrees C and a 5% weight loss was observed in the range of 354-465 degrees C.