Ubiquitin associated protein 1(UBAP1) is a novel member of UBA domain protein family, located at human chromosome 9p21-22 where loss of heterozygosity frequently occurs in nasopharyngeal carcinoma. Through integrated analysis of public database such as EST, Unigene in silico and direct sequencing of cDNA clone, full-length cDNA sequence of murine homologoue of human UBAP1 gene was identified, which is 2 676 bp long and encodes a putative protein of 441 amino acids with a UBA domain. There is an average of 89% identical residues between mouse and human UBAP1 protein. Digitalized expression analysis based on EST data showed that mouse UBAP1 gene expressed ubiquitiously and strongly in most of mouse normal tissues.