A pot experiment of planting two cultivars (Xiushui-48 and Bing-9652) of rice in two soils with different total Se levels was conducted to study dynamics of Se uptake and accumulation in these plants during different growing periods. Results showed that with the plants growing and entering their jolting stage, rice began rapid Se accumulation. The amount of Se accumulated by the plants during the period from jointing to booting accounted for 65% ~77% of the total Se accumulation of the plants, suggesting that this is a key Se absorption period of the plants. At the seedling stage, Cultivar Xiushui-48 absorbed more Se than the other because its roots are more capable of absorbing selenite, while the two cultivars differed slightly in biomass and Se uptake at the maturing stage, regardless of whether the soil was high or low in soil Se, cultivar Xiushui-48 was more higher than the other in Se content in grains, which suggests that Se uptake by rice is not constant. Compared with cultivar Bing-9652 in the low Se treatment, cultivar Xiushui-48 in the high Se treatment was high in capacity of accumulating and translocating Se. The difference between the two cultivars in Se distribution in grains and other plant organs was the major cause leading to difference in Se content in grains between the two. In the low Se treatments, the organs of rice plants were in the order of roots > shoots ≈ leaves > seeds in terms of Se content, showing a trend of accumulating in vegetative organs, whereas in the high Se treatments, they in the order of roots > grains > leaves > stems, showing a trend of accumulating in grains.