A recombined E. coli-A. latus shuttle vector plasmid pKTC32 harboring the cloned phbC gene from Alcaligenes latus was constructed, and transformed by electroporation into the parent A. latus in order to amplify the PHB synthase. The rate of PHB biosynthesis and content of PHB increased significantly after the transformation of the cloned phbC gene, plus the plasmid stability remained relatively high at around 85%. The enhanced PHB biosynthesis mechanism produced in the transformant A. latus was investigated by measuring the variations of enzyme activities related to the PHB biosynthesis.