本文以韩礼德语法隐喻为指导研究了及物系统中作为环境成分的 IN 介词短语。介词或介词短语因其高使用频率和丰富的语义变化，历来为研究的热点，并成为语言学习和习得的必要组成部分。因此，人们已经从不同视角，如认知语言学，语料库语言学和应用语言学等，开展对介词或介词短语的研究；不难发现，前人研究多关注介词或介词短语的认知机制及其搭配和分布对语言学习及习得的影响，然而，从功能视角却少有描述。本研究参照系统功能语法展开，而系统功能语法由韩礼德提出，是以意义为基础的理论。本文中，韩礼德的环境成分类型表将用以 IN 介词短语分类，以此为基础，介词 IN 引导的语法隐喻进一步得以识别，进而以语法隐喻理论对其进行阐释。该研究所有语料均来自英国国家语料库。 在系统功能语法中，语法隐喻理论被普遍认为是阐释语言使用的革新性成果。然而，其以前的应用主要局限于小句级，而小句级以下留有研究空白，具体而言，词组、短语级和词级。本研究主要将语法隐喻运用于词组、短语级，以 IN介词短语作为该案例研究。 本研究发现，尽管大多数介词 IN 短语表达空间环境成分，但是，仍有许多可被鉴别为隐喻性表达。具体而言，首先选出 5000 个含有介词 IN 的实例，其中 2738 个实例，即介词 IN 短语充当及物系统的环境成分为本研究的有效数据。在 2738 实例中，61.76%的 IN 介词短语作为空间环境成分，其中 38.24%用以实现非空间环境成分。在此非空间环境成分表达中，可以发现 14 个子类，即，从最高百分比到最低百分比排布依次为，[跨度：持续时间]，[处所：时间]，[方式：性质]，[原因：目的]，[或然：条件]，[方式：方法], [角色：身份]，[角度：观点]，[原因：理由]，[伴随：随同]，[或然：让步]，[或然：默认], [方式：程度]，和[原因：利益]。根据语法隐喻界定性特征，即，语义耦合，形式和意义间张力，同族系和级转移，五类隐喻性表达可以描述为语法隐喻，即[或然：默认]， [原因：目的]， [或然：条件]，[原因：理由]，和[或然：让步]。基于 13 类成分语法隐喻框架，第九类从连词到介词或介词短语可以来阐释[或然：默认]，[原因：目的]，[或然：条件]，[原因：理由]，和[或然：让步]此五类语法隐喻形成机制。 该研究意义存在以下几个层面：1. 该研究是对作为及物系统中环境成分 IN介词短语的初步探究；而以前从系统功能语法-语法隐喻视角对此类问题少有系统研究，故可能开启未来一个新的研究领域；2. 词组短语级的 IN 介词短语研究将为语法隐喻使用范围做理论补充并论证其在阐释环境隐喻性表达的有效性。3.该研究对具体语境下的 IN 介词短语给予系统描述，将对相关教学活动产生一些启示。4. 它还将对探究其他介词和语法隐喻理论提供一定的借鉴。

This study investigates IN phrases as circumstance in the transitivity system under the framework of Halliday’s grammatical metaphor (GM, hereafter) theory. The study of prepositions or prepositional phrases has been a heated issue due to their highly frequent use and full meaningful varieties and thus constitutes part and parcel of language learning and teaching. For this reason, prepositions or prepositional phrases have been studied from different perspectives, such as cognitive linguistics, corpus linguistics and applied linguistics. It can be found that those previous studies mainly focus on the cognitive mechanism of prepositions or prepositional phrases and the effects of the collocation and distribution of them on language learning and acquisition, with little account of them from the viewpoint of functions. The current study of prepositional phrases is implemented with reference to Systemic-functional Grammar (SFG, hereafter), which is proposed by Halliday and considered as a meaning-based theory. In this thesis, Halliday’s typology of circumstantial elements is employed to categorize the IN phrases, on the basis of which some GMs introduced by IN will be identified and further interpreted within the framework of GM. All the data for this study are from British National Corpus (BNC, for short). In SFG, the GM theory is generally viewed as an innovative achievement in the interpretation of language use. However, its previous study is mainly confined to the clause rank, which leaves some research spaces below the clause rank, specifically speaking, the group/phrase rank and the word rank. The aim of the present research is the application of the GM theory to the group/phrase rank and takes the prepositional phrases introduced by IN as a specific study. It can be discovered that although the majority of IN phrases express spatial circumstance, quite a few can be identified as metaphorical expressions. Specifically speaking, 5000 cases containing the preposition-IN will be chosen and then 2738 ones in which IN phrases serve as circumstance in the transitivity system are valid data for this study. In the 2738 instances from BNC for the analysis, 61.76% of them serve as the spatial circumstance, and 38.24% of them are deployed to realize the non-spatial circumstance. Among the non-spatial expressions 14 categories can be discovered and they are [Extent: duration], [Location: time], [Manner: quality], [Cause: purpose], [Contingency: condition], [Manner: means], [Role: guise], [Angle: viewpoint], [Cause:reason], [Accompaniment: additive], [Contingency: concession], [Contingency:default], [Manner: degree] and [Cause: behalf], ranging from the highest percentage to the lowest percentage. According to the defining properties of GM, namely, semantic junction, tension between form and meaning, agnation and rank shift, five kinds of metaphorical expressions can be described as GMs, that is, [Contingency:default], [Cause: purpose], [Contingency: condition], [Cause: reason] and [Contingency: concession]. On the basis of the thirteen types of elemental GM, the tenth type of GM from conjunction to preposition/prepositional phrase can be employed to interpret the generation of [Cause: purpose], [Contingency: default], [Contingency: condition], [Cause: reason] and [Contingency: concession] as GMs. The significance of this study lies in the following respects: firstly, it makes a preliminary investigation of IN prepositional phrases as circumstance in the transitivity system, which is seldom studied systematically from the perspective of GM within SFG, thus possibly opening up a research area in the future. Secondly, the study of IN phrases under the group rank scale will make a theoretical supplement to the scope of GM and corroborates the validity of it in the interpretation of the metaphorical expression of circumstance. Thirdly, this study presents a systematic description of IN preposition in particular contexts of situation and can offer insights into the corresponding teaching activity. Finally, it can provide implications for both the study of other prepositions and the GM theory.