The experiments were carried out to study the effect of high - effective silicon fertilizer application on late rice yield in southern mountain region of Zhejiang province. The most proper rate and method of the application were studied as well. The resuits showed that the grain yield increased by 15% - 18.5% when 150 -450 kg per hectare of high- effective silicon fertilizer was applied to the late - rice, because silicon could improve adversity tolerance and disease resistance of rice and increase spikelet bearing number and 1000 - grain weight. The most proper rate of silicon fertilizer application was 250 kg per hectare, and the most proper application was 50% silicon fertilizer as basal and 50% foliar spray at boot stage.