A protease inhibitor gene has been isolated from native cowpea (Vigna unguiculata L.) cv. 130 from l-ZAP II genomic library. The nucleotide sequence of this genomic clone shared 86% homology with a cowpea trypsin inhibitor f IV mRNA, and 81% with Bowman-Birk protease inhibitor genes of soybean. The isolated gene had TATA and CAT signals in the 5' upstream region. The longest open reading frame had 504 bases, encoding 167 amino acids from the predicted coding region. The active serine centers of this protein was found between 105-158 amino acid residues, with a 69 amino acids long signal peptide in its N terminal.