Electric demand management program has received a great deal of attention from the researchers to operate the power systems economically. It contributes to reliability of the electric power supplies and improves the efficiency of the facilities in the power system. Accordingly, the generation cost and maintenance cost are saved and electricity prices are stabilized. Currently, KEPCO (Korea Electric Power Corporation) and KPX (Korea Power Exchange) manage electric demand management program in Korea. KEPCO has managed electric load by Demand Adjustment Program of Designated Period (DAP of DP), Demand Adjustment Program of Advance Notice (DAP of AN), Direct Load Control and Average Interruptible Load. KPX has opened in the Demand Resource Market (DRM) when the operation reserves are predicted in the below of 5,000MW. Electricity supply and demand planning can be set up more stably with the exact evaluation of load management potential and peak reduction. In this paper, we analyze load management programs in the past, and represent the contributions for Electricity Supply and Demand Planning. Finally, the future development direction of electric demand management programs and demand response programs in Korea is represented.