A new monomer, 2,5-bis(4-carboxy methylene phenyl)-3,4-diphenyl thiophene (V) has been synthesized and characterized by physical and spectroscopic methods. A series of eight aromatic-aliphatic polyamides was prepared from the (V) and different aromatic diamines using Yamazaki's direct phosphorylation reaction. The polyamides were characterized by IR spectroscopy, viscosity measurements, and thermal analysis. An excellent yield of these polyamides was obtained, with inherent viscosities in the range of 0.28 to 0.67 dL/g, and the polyamide were readily soluble in aprotic polar solvents such as N-methyl-2-pyrrolidone, N-N-dimethyl acetamide, dimethyl sulphoxide, and so forth. Polyamides could be cast into transparent and flexible films. They had glass-transition temperatures of 225-273 degreesC. When evaluated by thermogravimetry, thermal analysis of the polyamides showed no weight loss below 311 degreesC, and the char yield in air at 900 degreesC was 55%-67%. The structure-property correlation among these polyamides is also discussed.