Abstract: A novel protein, bcOBP was found in bovine colostrums. This protein belongs to the lipocalin superfamily, most of them are secretory proteins. The aim of this study was to investigate organs that express bcOBP mRNA with its expression level and to determine the origin of bcOBP in the bovine body. We quantified bcOBP mRNA in several organs of bovine body with qPCR. The expression was found in the principal organs (heart, liver and kidney), node and mammary gland. In addition, the expression level of bcOBP in heart is as much as in kidney among principal organs. Further, in situ hybridization analysis opened the possibility that bcOBP in bovine colostrums might be secreted from the mammary alveolus in mammary gland. Our study provides a fundamental concept for lacto protein.