Abstract: Systemic-Functional Linguistics(SFL) is an "appliable linguistics" theory devoted to the theory guiding practice,which provides very powerful theoretical evidence for discourse analysis.Cao Xueqin gives a detailed and vivid depiction of Granny Liu in Dreams of Red Mansions.It is found that the analysis of the construction of interpersonal meaning of "Granny Liu's entering Grand View Garden(GVG)" with the theory of SFL coincides with the discourse context of "Granny Liu's entering GVG".Thus the appliability of SFL to discourse analysis has been further verified.