Man, with all this powers and prowess, depends totally on other biological entities for all his nutritional needs, he is even unable to synthesize certain biochemical's essential for his own normal function. That man has survived such serious biochemical limitations attests to his ability to exploit the biological environment to his own advantage; this began with plans and animals, and was soon extended to microbes and eventually to cultured animal and plant cells and tissues. Which includes fungus also yeast and mushrooms coming under the class mycota (fungus) have great economic value. Health security through balanced and nutritious diet becomes the first priority for agricultural development after attaining self-sufficiency in the production of food grains in our country. In view of the widespread malnutrition, combating protein malnutrition deserves prime importance. The problem is more serious in India because the majority of our population is vegetarian and therefore, animal protein is not available or acceptable. The protein malnutrition can be combated by increasing the mushroom production and details about the mushrooms are given in this book.