This dissertation is a multidimensional analysis of a debated topic in Classical Chinese (VI to 111 century b.C.) Syntax, unmarked passive sentences. The main data of the analysis consists of all the sentences with patient subject, with transitive verbs and without passivizing particles, in the text of Mengzi (IV century b.C.). The appropriateness of using such a label, which refers prototypically to European languages with their rich verbal morphology, to describe a very different language situation, has been put into question. A typologically based characterization of passive is proposed, which relies on lexical factors (transitivity), syntactic factors (object deletion and subject properties) and discourse factors (defocusing of the agent, topic properties and parallelism). As Mengzi represents the standard and most investigated example of Classical Chinese, this study based on a single text and on about 30 sentences can throw light on a wider language situation. Constant reference to other Classical texts, from Zuozhuan and Lunyu to Zhuangzi and Hanfeizi, is provided to confirm, expand and revise the interpretative framework. The purpose of the dissertation is 1) to provide a multidimensional framework of lexical, syntactical and pragmatic factors to analyze and classify the data. The factors are not mutually exclusive, and the classification is not an aim in itself, but a preliminary step to: 2) clarify the status of the patient preverbal NPs, providing the distinctive features of patient subjects in contrast with topicalized objects, both in presence of explicit markings and when the overt distinction is neutralized; 3) evaluate, in relation to my data from Mengzi, the more general issue of the influence of semantic and pragmatic factors on word order and deletion in Classical Chinese, and the explanatory power of topic prominence in contrast with subjecthood and transitivity; 4) delineate possible development of this framework of analysis to deal with lexical causativity and anticausativity, the role of construction grammar in the analysis of Classical Chinese and the relationship (synchronical and diachronical) between passive and causative contructions.