Abstract: Bis（4-aminophenyl）-9，10-dihydro-9-oxa-10-phosphaphenanthrene-10-phosphoryl ethane（ADOPPE）and 2-（3-amino phenyl）-5-amino benzene imidazole（i-DAPBI）as the diamine starting materials，were introduced into the dianhydride 4，4′-（hexafluoroisopropylidene）diphthalic anhydride（6FDA），3，3′ ，4，4′- biphenyltetracarboxylic di- anhydride （BPDA），3，3′ ，4，4′- benzophenonetetracarboxylic dianhydride（BTDA）with various ratios of amount of substance via twostep polycondensation to obtain several different series of polyamic acids （PAAs）， and the corresponding phosphorous- containing polyimides with imidazole（PI） were prepared by thermally imidization. The structure of polyimides was characterized with FTIR. The comprehensive performances were compared with DSC，TGA，UV-Vis，solubility test and mechanical property test. The results showed that the synthesized PI films had excellent thermal properties，high light transmittance and good mechanical properties，and the PI-a series could be dissolved in organic solvents well.

Key words: phosphorous-containing polyimides with imidazole, thermal properties, light transmission, mechanical properties