副文本体系的建立是基于三个视角:空间、时间与功能。序跋作为副文本的重要类型之一,在空间层面上属于发散区副文本,空间距离是其重要的形式标记;在时间层面上属于复合时期副文本,生成时间具有灵活的跨度性;在功能层面上属于复合功能副文本,兼具语篇的构篇功能和人际功能。 The establishment of the subtext system is based on three perspectives: space, time and function. Preface and postscript is one of the important types of subtext. It belongs to the subtext of divergent region in spatial level, and its spatial distance is an important formal marker. On the temporal level, it belongs to the subtext of compound period, and the generation time has a flexible span. At the functional level On the sub-text is a composite function, both discourse structure articles and interpersonal function.