Increasing the electrical load on the power system requires an increase in the number of power plants and enhancement of the transmission lines. Commonly, the power plants have located in the remote area that geographically very far from the load center. It causes the system to become more complex, susceptible to disturbance, affected to voltage profile, and increasing the power losses. To improve the voltage profile and to overcome the power losses, the compensation device technologies such as Flexible AC Transmission System (FACTS) devices have been implemented in the transmission line. The FACTS devices based on the Static Synchronous Compensator (STATCOM) is implemented to compensate the power system. However, determination of the optimal location and sizing are more challenging to be determined. Therefore, the Bacterial Foraging Optimization (BFO) method which has main process such as Chemotaxcis, Swarming, Reproduction and Elimination-Dispersal, is proposed to determine the optimal placement and sizing of the STATCOM. This analysis was conducted by using the 500kV Java-Madura-Bali (JAMALI) power system data. Based on the simulation result, shows that the BFO can determine the optimal placement and sizing of the STATCOM such that voltage profile and power losses can improve more effectively compared by capacitor bank implementation. The implementation of the STATCOM and capacitor bank can reduce the active power losses up to 11.997% and 8.709% respectively. In addition, the implementation of the STATCOM and capacitor bank can also maintain the voltage profile in each bus at the allowable voltage limit i.e. 0.95-1.05 pu.