Abstract
Genetic heterogeneity plays an important role in exploring the interplays of microorganisms. Competitive exclusion principle is the main principle that governs causative agentries of diseases competition. Identifying coexistence mechanisms is a core issue for studying the interactions of multi-strains. In this paper, we are concerned with the dynamics of a two-strain SIS epidemic model with general incidence rate on complex networks. We derive the basic reproduction numbers and the invasion reproduction numbers associated with each strain, which determine the competitive, exclusion and coexistence of the two strains. We strictly prove that the competitive exclusion principle holds in a global sense and the endemic equilibrium coexists uniquely and globally. Numerical examples visibly illustrate the evolution of the two strains.