Various graph theoretic properties of the commuting graph ∆(GBn)of a generalized Brandt semigroup,including diameter,girth,matching number,independent number,and clique number are investigated.The conditions under which the commuting graph of a generalized Brandt semigroup is Eulerian,Hamiltonian,planar and perfect are given,respectively.The structure of the commuting graph of a generalized Brandt semigroup is explored.