Environment is the sum of all factors and forces that affect life of all the organisms. All the organisms depend upon the environment to sustain their life. The activities of organisms affect their surroundings in many ways, which in turn may affect the organisms themselves. Thus, there is an intimate relationship between organisms and their environment. A careful observation of the environment would reveal a close interaction between the organisms and the environment they inhabit. A healthy environment is essential to satisfy the organism’s basic necessities, such as food, shelter, water, oxygen, the optimum temperature. One way to deal with this situation is by providing knowledge about environment. This book “Environmental Science” is based on general knowledge and aspects of environment. I have tried my best to make this book timely and have included important and necessary aspects. This book may also be useful to people in interested field and teachers.