During past 2000 years,the distributing area of three kinds of wild rice, Oryza rufipogon Griff., Oryza officinalis Wall and Oryza meyeriana Baill in China decreased 45 06%,from 2 495 575 to 1 371 094 km 2;nortern latitudinal limit of their distributing area moved 9°49′,1140 km south,from 38°3′ N to 28°14′N.Whereas,the distributing area of rice( O.sativa. L)increased 135%,from 4 081 860 km 2 to 9 600 000 km 2;the northern limit of its distributing area moved 15°29′,1700km,toward north,from 38°N...