In this paper,by use of equivalence operators δi and semi-equivalence operators δi we study the clustering problems of complex systems,present δ(1,3)disconnection principle,dual transformation principle and large-scale systems decomposition principle for analizing and operating complex systems,discuss inter connectivity and disconnectivity of complex systems in detail and present some related theorems.Finally,we discuss the levels of systems according to pansystems clustering approach proposed in this paper.