The history of the dykes built to reclain land from marshes in the Dongting Lake area can be dated back to the Neolithic Age. In Han and Jing Dynasties the construc-tion of such dykes began to take shape. In Tang Dynasty the protective embarkments in the lakeside area underwent three renovations of pretty long scale. In Southern Song such construction got a steady development, but the ability of the lake to adjust the flood from Yangtze was weakened, hence the flood became more serious. In the early period of Ming Dynasty some defensive walls surrounding the villages were re-novated Yuan Jiang, Hua Kong, but it often happened that the walls collapsed and merged with the lake. In Qing Dynasty it was first of all encouraaged and supported to build dykes in the lake area to reclaim land from marshes, but later because of the constant flooding, such dykes were prohibited. The abovementioned history proves that past dykes so built were the natural tendency of the accumulation of the increasing of population, but too many such dykes will cause the drastic revenge of the nature.After liberation, the construction of such dykes in the lake area saw a new deve-lopment. From 1949-1979, the dimensions of the inner lake were reduced by nearly 1 500 000 mu, The dimensions of the outer lake were reduced by 1610 km!. The cul-tivated fields were increased by 2 750 000 mu. The total outputs of the main crops like food, cotton, bast-fibre plants and so on were increased and certain amount of econo-mic effect was achieved. But at the same time a series of complicated prpblems came out:1. The accumulation of silt at the bottom of the lake was quickened.2. The water source for fighting the drought were cut down.3. The calamity of flood, waterlogging and soak became more serious.4. The navigation channel was blocked up.5. Fishery was squeezed out.6. The economic effect of production was reduced.Based on the above discussion, the author presents his suggestions concerning the renovation of the lake area:1. Before the flood from Yangtze is completely under control, the blind construc-tion of the dykes to reclaim land from marshes should be strictly prohibited.2. To make a plan for channelling flood and emptying the silt, gradually changingthe passive situation of the lake above the fields.3. To merge the fields with the lake properly.4. To further raise the ability of the lake area to fight the flood and to drain the logging water, and set up a good system of planting as well as adjust the layout of the crop5. To raise the output of the single crop greatly and develop a diversied economy in agriculture. Then the construction of the base of the marketable grain could be assured.