A novel gene, named embryonic develop associated gene 1 ( EDAG -1) and abundantly expressed in human fetal liver tissues, was isolated by screening a human fetal liver cDNA library and the 5' RACE. The full length of EDAG-1 mRNA is 2 166 bp, with an open reading frame of 1 452 bp neucleotides, encoding a 484 amino acid protein. No domain or motif was found similar with other genes by Blast program. Two copies of AUUUA motif in 3' non-translated region show instability of its mRNA. The molecular weight of the protein is 55.3 kD identified by the translation in vitro. EDAG-1 is specifically expressed in hematopoietic tissues, and is quickly down-regulated during the differentiation of K562 cells induced by hemin and EPO. These results show that EDAG-1 is related to the regulation in hematopoietic system and the development of leukemia.