In this paper we present a sketching survey of the development of systemic functional grammar(SFG),and concentrate on the elaboration of the major concepts of SFG,such as the system networks,the rules for the realization of systemic choices,alongside categories and conflation processes of SFG metafunctions.We aim to present a clear picture of the theoretical origins,development and current structures of SFG,such that it can be a guide for language teachers to enhance their teaching and research work.