Mechanical Engineering is the application of knowledge for the advancement of human civilization. It covers the field of theory, analysis, design and practice (manufacture, operation and maintenance) of machines. As the basic course, this book 'Mechanics of Machines-I' has been written to meet the basic requirements of the subject Mechanics of Machines (Theory of Machines). This book embraces all the basic concepts and problems pertaining to each chapter. This book has been divided into four major chapters dealing with basic concepts and ideas of Mechanical Engineering in a detailed and lucid manner. The salient features of this book are that all necessary theoretical information in concise form, illustrations and step by step problem solving approach in such a way that the reader of this book will grasp the subject matter easily. With the above mentioned features, the author is sure that this book will serve as self study reference.