Yangtze river valley holds a significant place in the cultural , heritage and economical importance in the history of china . it is beileved that traces of human existence was found along the riverbed about 2 millions year ago. since then development along these region took place. The river bed is rich in alluvial soil, which is an ideal soil for rice cultivation. In Past archeobiological studies have found the traces of wild varieties of rice grain in the middle and lower ranges of the river valley. looking into the evidence and traces found along these area , it is known to be the origin of rice cultivation. Infact china consumes the largest amount of rice.