This book has been designed to covers the undergraduate syllabus of Commercial Plant Breeding as per 5th Dean Committee report of ICAR. The subject matter has been presented through fifteen chapters and three parts to clearly specify the different topics for convenience of the readers. The first introductory part briefly explains modes of reproduction in crop plants, types of improved seed, development of inbred lines, development of hybrids using A, B and R lines and variety release procedure. The second part seed production, certification and testing describes principles of quality seed production, hybrid seed production in field and vegetable crops, seed certification, testing seed quality and maintenance breeding. The third part of the book have been dedicated to principles of DUS testing, PPV and FR Act 2001, intellectual property rights and alternative strategies for line and cultivar development. Related terminology has been given at the end for ready reference. Hope, this volume would be useful to the students, teachers and researchers engaged in the field of Plant Breeding, Genetics and Seed Technology.