Rice is a staple food crop of India which occupies the largest area of 44 m.ha among all the crops grown in the country and is the largest in the world. To meet the demands of increasing population, The present production level of around 93 million tonnes of rice, need to be increased to 120 million tonnes by the year 2020. Distribution of genetically pure seeds to farmers will facilitate complete heterotic expression of hybrids. Traditionally, morphological traits have been used extensively in purity control of hybrid seed and variety identification. The main disadvantages of these methods are time consuming and space demanding aspects because it requires collection of extensive data at different locations.With the advancement of molecular biology, the DNA markers or molecular markers can be effectively and efficiently employed for identification of the genetic purity of hybrids at genomic level. The utility of different types of molecular markers like RAPD, AFLP, STMS, SSR etc.for testing the hybrid seed purity has been demonstrated in many crops (Yashitola et al., 2002).This book, provides the useful information for the Seed Industries, Seed Testing institutes, Seed Analysts.