Alkaline (alkalized) soil refers to a type of soil in which the soil colloid contains a high level of exchangeable sodium (alkalinity > 15%), showing a strong alkaline reaction (pH > 8.5), with poor soil structure, and without a high salt content. Alkaline soils and saline soils often coexist, which are collectively called saline-alkaline soils. Different from the stress caused by neutral salt (NaCl) in the saline soil to the crops, the stress caused by the alkaline salt (NaHCO3 and Na2CO3) in the alkaline soil not only includes ion toxicity and osmotic stress, but also more serious damage to crops due to the high pH outside the roots. The traditional method of “reducing alkaline content with planting rice” can improve alkalized soil on a large scale and increase agricultural land area. Therefore, it is important to understand and master the adaptability of rice to alkali stress, create efficient cultivation technique of rice for alkaline land, and then develop new rice varieties with alkali resistance, which are of great practical significance for improving the utilization rate of alkaline (alkalized) land and ensuring regional food security. Based on recent domestic and foreign progresses reported, this paper reviews the rice alkali-tolerance in aspects of morphology and physiological characteristics, gene location and cloning, germplasm identification and screening, and genetic improvement, and present prospects for future research on alkali tolerance of rice. The purpose of this article is to provide a theoretical basis for the improvement of soil and grain by “reducing alkaline content with planting rice”.