Aim To investigate the physiological role of Battenin interactive protein (BIP) and screen the proteins interacting with BIP in human fetal cDNA library. Methods The cDNA coding BIP and binding domain of plexA were recombined as a “bait", proteins interacting with BIP were screened from human fetal cDNA library by yeast two-hybrid system. Results Seven positive clones were isolated through plexA-HERPUD1 screening the human fetal brain cDNA library by yeast hybrid technique. One of them has 99% homology with the TEGE gene of human, which codes Bax inhibitor-1 (BI-1)(testis enhanced gene transcript). Bioinformatic analysis shows that: Bax inhibitor-1 which interacts with BCL-2 and BCL-X is a gene transcript enhanced factor and a regulatory factor of apoptosis and probably associated with gene expression regulation for cell's growth and development. The gene that codes Bax inhibitor-1 is TEGT located in chromosome 12q12-q13, containing 8 extrons and 7 introns. Conclusions The interactive proteins of BIP were screened through yeast two-hybrid system successfully, and one of the proteins is Bax inhibitor-1. Bax inhibitor-1 is a gene transcript enhanced factor and a regulatory factor of apoptosis and probably associated with gene expression regulation for cell's growth and development