A series of organosoluble polyimides with various aromatic tetracarboxylic acid dianhydrides was prepared from diamine monomers using one- and two-step methods. All the polyimides were soluble in aprotic solvents such as NMP, DMF, DMAc, and DMSO. The polyimides showed excellent thermal stability and good mechanical properties. The glass-transition temperature of the prepared polyimides ranged from 210 degrees C to 325 degrees C. All the polyimides formed tough transparent films, with tensile strength of 84- 118 MPa, 8%-12% elongation, and 1.5-2.3 GPa modulus. These polyimide films were found to have a dielectric constant in the range of 3.29-3.80 at 1 kHz and 3.14-3.76 at 10 kHz and low moisture uptake, 0.52%-1.10%. (c) 2006 Wiley Periodicals, Inc.