Agricultural extension service as one important part in farming system has proved its role to the production enhancement in the New Order era. This extension element with supporting facilities from central government contributed to the achievement of lndonesian's rice self-sufficiency in 1984. Unfortunately, toward and after decentralization, agricultural extension as well as agricultural sector showed decrease performance. This paper examines the roles of agricultural service agency in Ogan Komering · Ilir (OK.I) Regency. to manage rice production before and after decentralization by which the local government are given more functions including managing agriculture. The production, changing of institutional including supervision pattern, and socio-economy of OKI Regency proved the importance of agricultural extension to enhance the better farming system.