High temperature stress caused by global warming posed a serious threat to rice high productivity. The increasing frequency and intensity of extreme high temperature stress have adverse effects on rice growth, development, and grain yield. Rice are susceptible to high temperature during booting, flowering, and grain filling stages. This paper reviewed the recent research progress in studying the effects of high temperature at 3 stages (booting, heading & flowering, grain filling) on rice grain yield formation. High temperature had detrimental effects on pollen development, anther dehiscence,spikelet fertility,and on accumulation and translocation of photoassimilates, grain filling and starch synthesis. Those effects subsequently resulted in grain filling rate and grain yield declining. Grain filling rate and grain yield were mainly parameters for evaluating rice tolerance to high temperature. On the basis of previous studies, this paper put forward several measures as genetic improvement, optimization in nutrient and water management, artificial auxiliary pollination, and application of plant growth regulators, which might mitigate rice high temperature stress.