A series of new polyamides were synthesized by direct polycondensation of the 4,9-bis(4-aminophenyl)diamantane with various dicarboxylic acids. The most polyamides had high inherent viscosities, ranging from 1.08 to 2.10 dl/g. Polyamides had tensile strength up to 92.8 MPa, and initial modulus reached 2.1 GPa. Although these polyamides were incorporated by the quite rigid diphenyldiamantane unit, surprisingly, all three polyamide films have tough quality. Dynamic mechanical analysis (DMA) reveals that the polyamides have three relaxations. Their a! relaxations occurred at high temperatures, ranging from 417 to 489 degrees C. All three polyamide films show rather high G＇ values (above 10(8) Pa), even at temperatures exceeding 400 degrees C. The glass transition of polyamide derived from (+/-)1,3-cyclohexanedicarboxylic acid appeared at 417 degrees C.