Copolyimides based on 4,4＇-bis(3-aminophenoxy)biphenyl (abbreviated to BAB) and pyromellitic dianhydride (PMDA) were synthesised with 4,4＇-oxydianiline (4,4＇-ODA) and/or 3,3＇,4,4＇-biphenyl tetracarboxylic dianhydride (BPDA). Basic property and melt processability of synthesised copolyimides were investigated. Crystallisation property of these copolyimides were dependent on contents of 4,4＇-ODA and/or BPDA. Melt processability of copolyimides obtained from BAB, 4,4＇-ODA and PMDA were dependent on contents of 4,4＇-ODA. Melt viscosities and Tg＇s of copolyimides obtained from BAB, PMDA and BPDA were decreased according to increase of BPDA contents.