Since medium and small manufacturing enterprises have , played a very important role not only in national economy but also in political and social relationships all of the countries in the world have paid favorable policies and programmes for protecting and promoting this sector. In Korea main ingredients of promoting policy for this sector consist of (1) encouragement to modernize facilities and rationalize operation (2) special priority in bank loan (3) promotion of industrial cooperatives (4) prevention of infringement by large industries. However, substantial investigation for problems incurred in medium industries has revealed that unless medium industries improve and raise their technological and managerial skillfulness for themselves all other measures are useless to solve the problems. This realization has induced all of the countries to render extension services on both of technology and management to assist and support their own effort for rationalization. Also in Korea during past 20 years many technical and managerial research institutes have rendered free consultancy services to medium industries by the support of government subsidy. Among them the joint extension services project performed by the Medium Industry Bank and UNDP during 1967 and 1975 might he listed as model case because of its broad and integrated activities and participation of foreign experts. We think many precepts should be :learned from the study of this project. Korean economy is expected to develop rapidly throughout coming'80 in spite of many obstacles, tut there is an apprehension that gap in of every facet between medium and large enterprises might he deepened and enlarged. To prevent the actualization of so-called dual structure of national economy and to promote stabilized medium industries with high added value productivity which are shown in well developed countries, consultancy assistance ana extension services should be strengthened much more than ever. Fortunately in 1978 legislation of "Medium and small industry promotion act" has paved the way for the systematic achivement of consultancy and extension services which shall be integrated by the government overall program. Under new framework thoughtfull accomplishment should be undertaken considering precious precepts obtained from past experience and failure. Special attention should be given to the technical liaison officer scheme, exclusive participation of only professional institutes, strict qualification and training for consultants for the future succsseful implementation.