Agrometeorological conditions for early rice growth at differentstages are classified by Fuzzy cluster analysis.A set of agrometeoro-logical models are used in simulation experiments on a computer for the growth and yield under possible combinations of the conditions. Influ-encing indices C_α and C are constructed as the criterion for the quan-titative assessment of agrometeorological conditions. The early rice growthand dynamic moditoring of yield from the terminal output provide infor-mation service and schemes for decision of early rice planting. Besides,the planting density in the area of Shanghai is discussed in terms of de-cision analysis.