The Proposed Work In This Paper Deals With the Congestion Problem In Deregulated Power System. Due to Congestion In a Deregulated Power System, Transmission System Is Unable to Accommodate or Transfer the Desired Power Transaction. This Problem Can Be Overcome By the Use of Flexible Ac Transmission Systems (Factss) Devices. Factss Devices Reduce the Flows of Power In Heavily Loaded Lines As a Result an Increased In Load Ability of the System. Moreover, It Will Improve the Stability of the System, Lowering Down the System Loss and Cost of Production. the Optimal Location For Installing Thyristor Controlled Series Compensators (Tcscs) Based Facts Devices Is Carried Out By Using Sensitivity Based Analysis Method. In This Paper Tcsc Optimal Location Is Determined By Using Real Power Performance Index, Reduction of Total System Var Power Losses and Based on Reduction of Total System Active Power Losses. Matlab Based Programming Platform Is Used For Validation of Proposed Work.