Abstract: The value set approach is a graphics-oriented method based on the characteristic polynomial of the system.It can be used to analyze the impacts of uncertain parameters on the system stability.This paper describes the implementation of the value set approach in the robust stability analysis of the large power system,including the treatment of large numbers,memory optimization,assessment and adjustment of system reduction,and application to Gamma-stability criterion.These techniques are vital for the actual application of the value set approach.Also the value set approach is compared with the widely usedμ-based approach in terms of their robustness stability analysis,stability margin calculation,parameter impact analysis,conservativeness,and computation speed.Finally,the North China system is used to illustrate the implementation of the value set approach and test the two approaches,which reflects characteristics of the two approaches.