Cowpea is an important warm-season grain legume. Cowpea has received relatively little attention from a research standpoint. Apart from improvement of specific traits, breaking the yield plateau is the major task. Towards this direction, pooling of yield contributing alleles has reached already saturation and hence requires alternative approach. Recently, it has been realized that morpho-physiological approach as an alternative to address such tasks. The present book highlights the importance of physiological traits such as photosynthetic rate, stomatal conductance, transpiration rate and chlorophyll content in determining the yield indirectly by manipulated sink and source relationship and further, the scope of introgressive hybridization in development of new plant type through transgressive segregants. And also gives highlights regarding breeding approach by selection of parents, generation of transgressive segregants based on heterosis of the population and the selection parameters. This information is of great useful to the researchers and breeders who are willing to work on genetic improvement of crop species through conventional breeding approach.