The essential oils are present in the specific cells called as glandular cells present in the plant part that may be anywhere on plant body. Upon rupture of these glands aroma come out which are volatile in nature and combination of all chemical constituents are fragrance what we get sense. Essential oils are used in perfumery, aromatherapy, cosmetics, incense, medicine, household insect repellent cleaning products, and for flavoring food and drink. They are also valuable commodities in the agricultural industries as anti-feedants, repellents, botanical insecticides, natural herbicides and growth boosters are still open to fascinating realms of research. All information's are confined in scattered manner and hence an effort has been made to collect all information's and compiled together and represented in this book in a simple manner to serve the basic concept to the readers. This book complied with five s' viz. 1. Introduction 2. General extraction method for essential oils 3. Market statistics for importance of essential oils 4. Individual medicinal and aromatic plants 5. New aromatic plants and their future research.