On Internet world's largestelectronic commercesight. Beginningwas the online book store which sells the book via Internet, but it expands the stock quickly, presently it has become the comprehensive electronic commerce sight which handles music CD and video, the electrification product and the toy etc. other than the book. In addition, worldwide it cooperates with famous New York auction house "Sotheby ' s",extendsthe hand to also the online auction market.