Tropical grasses have been widely utilized as warm-season grasses in the warm temperate zone since the early 20th century because of their high yields as well as for perennial forages in their native tropical areas. The high yield of tropical grasses is mainly due to C₄ photosynthesis. However, the soaring demands for animal production sparked by economic development in tropical countries mean genetic improvement of such grasses is urgently needed. Considerable breeding efforts have been made to create and develop new tropical grass cultivars, although direct selection from natural populations remains the main method used for breeding. Cross-breeding has not proliferated due to a lack of genetic information concerning the polyploidy, high sterility, outcrossing, and apomixis of these grasses, although several of these difficulties are starting to be resolved by advanced research using molecular biology tools. These tools are an effective means of achieving genetically improving of tropical grasses, and further development is anticipated. In this review, achievements in the improved guineagrass, brachiariagrass, sorghum, and zoysiagrass are introduced and discussed.