Abstract: In the paper, experiments with the graminaceous crop-rice and wheat were carried out by using water culture and sand culture to study the relationship between the uptake of silicon by graminaceous crop and silicon supply of the different growth period. The preliminery experiment results showed that the most efficient time for applying silicon fertilizers was at tillering and jointing stage. According to the uptake characteristic of silicon by rice and wheat, we have suggested that apply silicon fertilizer at proper growth stage of the graminaceous crop.