It is the era of modernization. The world is leading towards enhancement of society and to the environment as well. Every growing step of man towards modernization of Nature science have has created hazards. Humans are politely and very honestly serving drudgery for the fruitful outcomes but the reverse results obtained. The field of science has taken an obligation of service for society but humans are taking disadvantages of this greatness of science. Getting deeper into modernization does have put man into risk. Thus, getting back to nature in this era is quite necessary offence. Authors feels that the book “The Comparative Study of Biologically Active Agents” would serve the need of reader at both graduate and post graduate level, beside research student of Microbiology, Biotechnology, Pathology and Molecular biology and Chemistry in the laboratory.