In this chapter we provide an overview of the topological field theory approach to topological insulators. We start by reviewing the topological field theory description of integer quantum Hall states, which also illustrates the general features of topological field theory approach. Then we reviewed the topological field theory approach of three-dimensional topological insulators and its physical consequences. In the last part of this section we discuss the generalizations of topological field theory approach to generic dimensions and other topological states of matter.