To identify zinc finger genes in human primary cultured erythroid progenitor cells, RT-PCR was performed using primers specific for the conserved sequence in zinc finger domains of mouse Friend of GATA-1. We identified a novel Krüppel-associated box (KRAB) zinc finger gene, ZNF317. Evaluation of full-length cDNA obtained by RACE showed that it encoded a protein composed of 13 Krüppel-like zinc fingers and a KRAB domain. RT-PCR analysis revealed four alternatively splicing products (ZNF317-1 through ZNF317-4). The ZNF317 gene has seven exons and is located in human chromosome 19p13. Northern analysis revealed that ZNF317-1 and ZNF317-2 transcripts were ubiquitously expressed, whereas ZNF317-3 and ZNF317-4 transcripts were detected only in lymphocytes, spleen, and lung. Competitive RT-PCR analysis showed that the expression of ZNF317 mRNA significantly decreased during erythroid maturation. In lymphocytes, ZNF317 expression was reduced in response to mitogenic stimulation. We propose that ZNF317 may play an important role in erythroid maturation and lymphoid proliferation.