Due to the asymmetric structure as well as bent conformation in 3,4'-dianhydride moiety, polyimides (PIs)which derived from 3,4'-dianhydrides exhibited higher glass transition temperatures (Tg), better solubility,lower melt viscosity and wider processing window as compared with the traditional PIs, attracted more and more attent on of scentisis1,2.However, it is complicated and expensive to synthesize the 3,4'-isomeric dianhydrides.Usually, the good performance of 3,4'-isomeric PIs could be achieved through the copolymerization of 3,3'-and 4,4'-dianhydrides with aromatic diamines3-5.Most researches of copolyimides are focused on PIs derived from isomeric biphenyltetracarboxylic dianhydrides (BPDA)4、 thioetherdiphthalic anhydrides (TDPA)5 and oxydiphthalic anhydrides (ODPA)6.It was found that the copolyimides drived from isomeric dianhydrides showed good thermal stability、 excellent melt processability and solubility.