The 58kD subunit gene of the human kidney vacuolar H^＋-ATPase has been successfully expressed in E.coli. The fragment of 58kD subunit gene was obtained by polymerase chain reaction (PCR). A clone encoding 58kD subunit was obtained by directly joining PCR product into the plasmid for expression by T7 RNA polymerase (PET). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analysis of cultured transformantsdemonstrated high expression of 58kD subunit gene. The product of 58kD subunit accounted for 50% of cytoplasmic proteins.