In a power system transmission network, there are some corridors which are lightly loaded whereas some of the corridors are critically loaded and thus power system is operating near to critical state. Flexible AC transmission systems (FACTS) plays a vital role in improving the power system performance, both the static and dynamic, and enhanced the system loading capability by rerouting the power flow in the network. Due to excessive cost, these devices must be located optimally. This paper suggests the suitable locations to enhance the system loadability with unified power flow controller (UPFC), a very versatile and powerful FACTS controller. The effectiveness of the proposed algorithm is tested and illustrated on 5-bus and IEEE 14-bus systems