Since 1980, progress of ME technological innovation too have been a great influence on work of manufacturing plant in leading industry such as automobile, electricity, iron and steel industry of Japan. On account of introduction of computer into maintenance part, we have objectively experiential skill of maintenance work and we have possibility to learn as knowledge. Namely, we substitute experiential skill of maintenance work for scientific technical knowledge. Nowadays, we have social needs to train new type labour force as technician. Thus, polytechnic colleges were established by Ministry of Labour. Object of cultivation in polytechnic colleges are training of technician which is acquired mental and physical ability. This paper attempts to analyze the actural state of polytechnic colleges. Namely, to put it more concretely, this paper makes clear analysis of training content and post of the work place, potential employment opportunities, treatment. Later, final purpose of this paper is to examine the function of official vocational training in Japanese system of human resource development. The results are as follows: (1) Graduates of industrial high school account for a third of trainee and they almost enter polytechnic colleges by industrial high schools recommendation. So, polytechnic colleges closely have relation to industrial high school education. (2) Character of training curriculum for technician which is acquired mental and physical ability, are as follows: Number of training hours at polytechnic colleges are fit for them in depertment of technology at four-years university. Practical training was attached importance for development of human resource which have specialized knowledge and technology. Internship is introduce into curriculum because of learning how to work at manufacturing plant and forming of vocational outlook. (3) Although technicians for occupation are not established in Japanese factory, graduates of polytechnic colleges merely are arranged not only operated occupation but also design, research and development, production control, process control, maintenance occupation. So that, polytechnic colleges play the part of technician training for small and medium enterprises. (4) Lastly, polytechnic colleges are not subordinate to small and medinm enterprises, but make a contribution to training organization of oriented external labour market in human resources development system at Japan.