A novel polyimide (PI) containing pendent biphenyl ester groups was synthesized from 3, 52 diaminobenzoic-4'-biphenyl ester (DABBE) and 3, 3', 4, 4'-oxydiphthalic dianhydride (ODPA) by a one-step hightemperature polycondensation in m-cresol. This PI is a semicrystalline polymer. Lots of short fine fibric crystals with length and diameter about 20μm and 1μm respectively disperse randomly in the PI film. The optical textures and the X-ray diffraction patterns of the PI solution and film show that the PI main chains are in the extended conformation and pack parallel to each other, and the pendent biphenyl ester groups occupy the space between the main chain layers, more or less perpendicular to the main chains. At the same time, mechanical and thermally stable properties of the PI film were investigated. The excellent mechanical properties of general polyimide films are reasonably maintained, the polyimide filmwith pendent groups showes higher tensile strength and modulus and lower Tg. TGA study showes a typical two-step weight loss behavior corresponding to the pyrolysis of pendent groups and main chains of the PI, respectively.