Petroleum oil was discovered in Assam,(situated in the north eastern part of India) by the British in Sept., 1825. First successful oil well was drilled in Oct., 1889 in Digboi well no.1 under the British Regime. India got Independence in August, 1947. Since then the Petroleum resources of Assam has been playing a vital role in Economic development not only of Assam but India also. But the potentialities of the said resource have not been utilized properly. Down stream project and ancillary industries have not been grown up to the expected level. For example, under the present reserve, production and refining capacity status of India, 11 more refineries like the Numaligarh Refinery Ltd. may be established in Assam. Such Refineries will generate more than 10000 direct employment opportunity and 40000 indirect employment opportunity and Rs.3,300 crore to the state treasury of Assam. This book would be useful for Govt. officials, researchers, students, academicians and industrialists'.