The photosynthetic rate，chlorophyll content and leaf area index of three buckwheat of F.gracilipes Var., F.cymosum and Chuanqiao-1 under four different soil fertilities were studied ,the results indicated that good soil fertility fit the growth of the wild buckwheat, although it was soil-barren plant. There was a great similarity between wild F.cymosum and Chuanqiao-1 of tartarian buckwheat.Compared with those of Chuanqiao-1 of tartarian buckwheat, the photosynthetic rate of wild F.cymosum was higher and peak value appeared late ,and the range of vary was greater and peak value appeared early