As the voltage and frequency stability problems of an interconnected power system are becoming increasingly complicated, emphasis should be further placed on coordination in a global perspective for their analysis and control. As traditional under frequency load shedding(UFLS) and under voltage load shedding(UVLS) devices operate independently using local frequency or voltage measurements, it is difficult to achieve real-time coordination and optimization of system-wide control. A new multi-agent system(MAS) based UFLS/UVLS method is presented to coordinate load shedding devices with local and remote information so as to guarantee control performance with less load shedding cost. Its key concept is based on the space distribution characteristics of voltage and frequency dynamics of different load buses while allowing for automatic adjustment of the load shedding control strategy according to the current system operating condition and the degree of disturbance. Time domain simulation results of the IEEE 14-bus power system and a real power system of China demonstrate the effectiveness of the new UFLS/UVLS scheme.