The present invention relates to a recombinant Escherichia coli having phbCAB originated from Alcaligenes eutrophus and an overproduction method of polyhydroxyalkanoate using the same, more precisely, a recombinant Escherichia coli ‘MG1655/pTZ18U-PHB’ or ‘JIL938/pTZ18U-PHB’ having phbCAB originated from Alcaligenes eutrophus and an overproduction method of polyhydroxyalkanoate comprising the steps of preparing transformed Escherichia coli having phbCAB originated from Alcaligenes eutrophus, inoculating and culturing the cells (growth phase), inducing the production of polyhydroxyalkanoate in the recomibnant Escherichia coli (stationary phase and producing phase), and inducing the extracellular secretion of the polyhydroxyalkanoate from the recombinant Escherichia coli. The method of the present invention facilitates not only overproduction of polyhydroxyalkanoate such as polyhydroxybutyrate by a simple batch culture but also industrial use of biodegradable polyhydroxyalkanoate replacing conventional non-biodegradable plastics by its simple and easy fermentation, separation and purification process.