West Bengal is one of the major rice producing states and a large number of germplasms are gradually being encroached for developmental and industrial purpose. This book represents my work whose aim is to characterize and find out the variability and diversity of the genetic base of 51 landraces of rice of West Bengal, India in light of kernel weight development with respect to agro-morphological features with special reference to 18 quantitative and 28 qualitative traits. The field experiment was done at the Zonal Adaptive Research Station, Krishnagar, Nadia,West Bengal during kharif seasons of three consecutive years of 2006, 2007 and 2008 following Randomized Complete Block Design. Univariate and multivariate analyses were done for 18 quantitative traits. To establish distinctness, a set of fifty one landraces of rice were characterized for 28 qualitative traits following standard Distinctiveness, Uniformity and Stability (DUS) testing guidelines of PPV & FR Act, 2001. The present study will be useful for breeders, researchers and farmers to utilize valuable germplasms in rice improvement and also to seek protection under Protection of Plant Varieties and Farmer’s Rights Act.