Abstract: Grain shape controlled by multiple quantitative trait loci (QTLs) is an important agronomic character, may have effects on both grain yield and quality in rice. With rapid advances in functional genomics and the advent of next generation sequencing technologies, more than 400 QTLs associated with rice grain traits have been identified, and some of them have been cloned. we discussed the factors affecting rice grain shape, cloning and functional analysis of some important rice grain shape controlling genes in rice.