Elementry Particles are very important in understanding the basics of particle physics. Almost all elementary particles have been detected in cosmic rays. This book has been written to help students of phusics in their understanding the Elementary Particles. Thinkers were pondering from earliest known times that how this whole universe is created and this quest is still going on. Studies of cosmic rays have given us great insight about the tiniest particles of the universe. This book gives introductory concept about Elementary Particles for beginner as well as for student of Physics. Efforts have been made to keep the language of the book simple and unnecessary derivation of formulae have been omitted so as to concentrate on the concept and to make the book useful for dufferent levels of students. Several books and reference materials have been referred in preparation of the manuscript and outhor is grateful to all these pioneers of elementary particle physics and legendry writers. Author also hopes that this book will be helpful to students of physics at college level and for general readers who wish to explore the subjects. Although every care has been taken to check misprints and typographic errors still a few may appear in the book. Author will be grateful if readers give their opinion for improving the book in future edition.