The purpose of this review is to introduce a new mapping technique, the chronometry transcranial magnetic stimulation (TMS), which can be used to delineate detailed time information of specific functioning target network by transiently creating a 'virtual brain lesion', thus disrupting the function of a given cortical target at different time window. Unlike neuroimaging methods such as functional magnetic resonance imaging (fMRI), chronometry TMS provided information about which language area contributes to performance of some specific task, and at what precise moment the contribution is critical. We shall highlight two aspect of chronometry TMS, that is used in language research either for understanding time course of language processing in normal subject or for measuring plastic reorganization of functioning network.