This paper presents power system stabilizer (PSS) model using artificial immune system (AIS) for power system controlling. PSS is a device that can be used to improve the damping of power system during low frequency oscillations. This study proposed the use of AIS algorithm for tuning the PSS parameter. AIS-based PSS has been successful in controlling the multi-machine under study. For multi-machine system consists of four machines, the application testing on the machine M1 to short circuit symmetrical three-phase, AIS-based PSS found that that good design results in this study. Overall, AIS-based PSS, Delta w PSS and Delta Pa PSS gives relatively good results in reducing oscillation system variables of which transfer electrical power, changes in angular velocity generator, and the generator terminal voltage. AIS-based PSS have the performance relatively better than Delta w PSS and Delta Pa PSS in terms of ability to reduce oscillation and speed of reaching a state of instability. Based on testing can be seen that AIS-based PSS rapidly deliver good results compared Delta w PSS and Delta Pa PSS primarily on the state of the system.