In Young-Dong area, many generators and new nuclear power plant will be added in the future. To carry the huge power to capital area, KEPCO is planning to construct a new 765KV transmission line. This report will look at new technology like HVDC, FACTS instead of construction of new 765KV transmission line. The many alternatives have been looked at, and compared the new plan to the present plan in power flow, transient stability. The purpose of this report is to show the possibility of application of new technology equipment.