The delta¹³C values of Japanese plants, mammals such as deer, monkey, wild pig, bear, shellfish, fish, and human bone in ancient times were determined by using the tandem accelerator of Nagoya University. From the delta* h13*sC values of human bones it was found that foods of the Jomon period (older than 3rd century BC), the Yayoi period (3rd century BC-3rd century AD), and the Yedo period (17th-19th centuries) were different. -- AATA