Abstract: The climatic regularity of insufficient illumination in rice area of Huainan in Jiangsu Province was showed, based on analysing indexes of insufficient illumination during the tillering stage of rice. And it was expounded that, because of insufficient illumination during the tillering stage of rice, the ratio of carbonhydrate and nitrogen contens in rice plants was imbalanced, values of a+b and a/b of chlorophyll in rice leaves changed notably, and photosynthesis was hindered. Therefore, it was caused that the number of tillers and dry weight decreased, the height of plant increased, the duration of gowth lengthened, and the degrees of disaster were different with various illumination levels

Key words: NULL, NULL