We establish a connection between the Chern number, which is an integer to characterize the global topological properties in Chern insulators, and two types of defects, which have the ability to reveal the localized topological features of the energy spectrum. On the basis of a two-band model, monopole and meron defects naturally arise from the geometric sense of the Chern number. It is discovered the monopoles take place at the Dirac points accompanied by a phase transition, implying the Chern number encounters a jump at the band crossing positions. When the bulk has a fully opened band gap, the merons emerge, whose topological charges is able to produce the Chern numbers of the two energy levels. This approach can be generalized to three-dimensional structures as well as other topological invariants. In this talk, I will present some recent progress about our method.