To analyse the possible interactions among multiple flexible AC transmission system（FACTS） controllers in a power system， an approach based on the singular value decomposition（SVD） is proposed for the analysis of interactions between thyristor controlled series compensator（TCSC） and static Var compensator（SVC）. The proposed approach is used to analyse the interactions between a TCSC and a SVC installed in the New England Test Power System（NETPS）. The simulation results verify the effectiveness of the proposed approach. And it indicates that the electrical distance has a strong influence on the interactions between TCSC and SVC. The interactions will be weakened when the electrical distances are increased， and vice versa.