This study focuses on the superimposed prepositions in modern Chinese, like “自从”, “自打”, “打从”, “从打”, “由打”. These prepositions is a special category of parallel superimposed prepositions in modern times Chinese. They are composed by monosyllabic prepositions with same or similar semantic meanings. These monosyllabic prepositions merge together and complement each other, so as to become a new category of disyllable prepositions with same semantic meaning. Chapter Two conducts a comparative analysis on superimposed prepositions and their superpositions on synchronic plane. Comparative analysis mainly takes three perspectives as below: first, the uses of prepositions are summarized from the perspective of semantic function. According to the semantic feature of the prepositions introducing the objects, we can categorize the prepositions into 4 types: a) time start, b) place start, c) scope start, d) origin. In each type of preposition, superimposed prepositions and monosyllabic prepositions have huge difference in the choice of object and VP. Second, the features of each preposition’s word order in sentence are analyzed, The syntactic position of preposition. The analysis focuses on the differences of before superposition and after superposition and also where these differences stem from. Finally, the topic function of superimposed prepositions is discussed. Almost all the superimposed prepositions can be place at the beginning of a sentence as a sub-clause or a preposition guide to introduce the objects followed, but they can’t be the topic in all the circumstance. Chapter Three explores the morpheme’s order within the superimposed prepositions based on the diachronic level. The morphemes’ order in a superimposed preposition are not random arrangement, but based on certain principle. Morphemes are mainly arranged in two ways: fixed order and temporary order, which is influenced by syntax, semantics, rhythm, etc. Fixed order is mainly decided by the lexicalization and part of speech. Temporary order is influenced greatly by the semantic meaning, and meeting the requirement of rhythm and avoiding repetition also influence the temporary order.