The LAI developments of sink-source type and dry matter production of different rice varieties were studied. The results showed: The LAI developments of the source-limited varieties (e. g. Liao-Jing5) belong to fast-rise and fast-fall type. The dry matter production is vigorous in the middle period of the development reaching 50 per cent of the total and the final yield of the total dry matter wes high, but the harvest index was low. The LAI developments of sink-limited varieties (for example, Xiuza) belong to middle-rise and middle-fall type. For production of dry matter, varietal differences were not obvious between middle period and later period, and the increase of dry matter was steady. The LAI developments Of source-sink staturated varieties (Qing Xi 96) appeared to be middle-rise and slow-fall type. The dry matter production was similar to the former. Analysing the grain yield, it was indicated at middle fertility the yield of middle-rise and middle-fall varieties With the LAI developments was high while the yield of fast-rise and fast-fall varieties was high at low fertility.