Abstract: The contents of Si in plant of thirty rice varieties (lines) were determined. Results indicated that Si contents in plant were ranged from 1.62 % to 2.66 % and the genotypic difference was significant. Plant accumulated small Si before heading, more than 3/4 of Si accumulation in plants were accumulated after panicle initiation. Genotypic difference of Si accumulation during different growth period was significant. The proportion of Si distributed in organs depended on growth stages and seasons. The proportion in stem, leaf and panicle were 43.36 % ,23.07 % ,33.57 % at ripening in early season and 33.23 % , 19.75 % , 47.02 % at late season. Si accumulation was significant correlation with yield, biomass production and N, P, K accumulation.