Frequency stability is one of important power system stability topics. The impacts of loads on the frequency can not be fully revealed with current frequency analysis methods. Therefore

a frequency factor analysis method based on the kinetic energy theorem and power flow tracing is presented. Based on this analysis method

an under-frequency load shedding strategy is designed. Load shedding factors are constructed assuming that the active power load supplied by the faulty generators will decrease

therefore specific loads can be shed accordingly. Simulation results on the IEEE 10-machine 39-bus system shows that the loads related to incident generators are shed specifically using the method proposed and it helps to quickly recover the system frequency. This work is supported by National Natural Science Foundation of China (No. 51507116) and State Grid Corporation of China.