The present research book "Rice: yield and its components role in high yielding variety development" based on research finding for rice yield, yield components, quality traits, existence of genetic divergence, association among different characters, combining ability variance and their effects, gene action involved in the inheritance of characters, heritability and genetic advance and estimate heterosis over better-parent and standard variety. Rice, one of the important cereal crops of India, is cultivated as pure culture mainly in Kharif. The crop is cultivated in large area but is characterized by very low productivity due to lack of high yielding varieties adapted to different seasons and agronomic conditions at different parts of country. Yield is a complex end product of a number of components most of which are under polygenic control. All changes in yield must be accompanied by changes in one or more of the components. The ultimate goal of any plant breeding programme is to develop improved genotypes better than the existing ones. This requires genetic amelioration through maximum utilization of allelic resources to develop ideal genotype.