It has long been proposed that secreted proteinases, including the matrix metalloproteinases, play an important role in tumor progression. Recently, human stromelysin-3, a new member of the matrix metalloproteinase family, was known to be expressed specifically in stromal cells surrounding invasive breast carcinomas and in tissues undergoing the active remodeling associated with embryonic development, wound healing and tumor invasion. But its physicochemical and biological characteristics are still not clearly known. We tried to make probes that may be useful for the study of stromelysin-3 experiments. The stromelysin-3 cDNA(108bp) was produced by reverse transcription-polymerase chain reaction from a fetal lung fibroblast treated with 12-O-tetradecanoylphorbol-13-acetate. And another stromelysin-3 DNA fragment(108bp) was produced by polymerase chain reaction using genomic DNA from human peripheral blood cells and fetal lung fibroblasts. These stromelysin-3 DNA products were cloned into pIH821 at the StuI site resulting in an in-frame fusion between maltose binding protein and stromelysin-3 and sequenced. The 45 kDa fusion protein was expressed in Escherichia coli XL1-Blue and detected by Western blot using anti-maltose bindging protein antibody.