The corpus-supported approach to SFG ( systemic functional grammar) is a new perspective of linguistics research，in which theoretical research and exploration are based on concordance and semi-automatic annotation． It is both theory-attestable and corpus-driven． A corpus-supported approach to textual metafunction is to model the cohesion system of textual meta-function into lexical strings and regular expressions that can be automatically retrieved; then the thesauri and regular expressions for different cohesive meaning serve as retrieved items for concordance，which are complemented with contextual wordlist( s) if necessary; the research finally aims at establishing the meaning probability profile of textual metafunction through observing and reasoning on the retrieved lines．