According to the documental accounts,the distri- bution of wild rice(O.perennis),the ancestor spe- cies of cultivated rice in ancient China is possiblymore northward than in the modern times.The ea-rliest rice grains unearthed from the Neolithic sitesexisted along the lower and middle reaches of the According to the documental accounts, the distri- bution of wild rice (O.perennis), the ancestor spe- cies of cultivated rice in ancient China is possibly more northward than in the modern times. The ea-rliest rice grains unearthed from the Neolithic sitesexisted along the lower and middle reaches of the