汉字分化是在原有字形的基础上造新字并分担原字记词职能的现象。这一现象贯穿汉字发展史的各个阶段，且在每个阶段都有不同的特点。战国至秦代的秦文字是汉字史上的关键一环，一方面它与战国时期的六国文字相比存在差异，地域特点明显；另一方面它在秦始皇“书同文字”政策的推动下成为全国通行的文字规范，具有承上启下的地位。对这一时期秦文字中的分化现象进行断代考察，具有重要意义。绪论部分简述了选题的研究意义、研究方案，梳理了已有的研究成果。古人对汉字分化现象已有所关注，宋人的“右文说”和六书学，清代王筠的“分别文”、徐灏的“古今字”等概念都与汉字分化相关；现代的汉字分化在理论研究上不断深入，材料得到扩展，但基于出土文献的分化研究成果比较零散，专门针对秦文字的分化研究较为少见。因此，基于出土秦文字资料研究分化字，有着不小的研究空间。第一章首先交代了战国时期秦文字与六国文字的关系，并把当时使用中的秦文字分成传承字、新造字两大类，明确了本文的研究对象“分化字”属于新造字，并说明分化字与相关概念的关系；其次说明了搜集整理秦系分化字的方法和原则，对分化方式的调查数据进行了分析。第二章依据母字、分化字的职能分工关系，把秦文字中的分化现象分为本义分化、引义分化、广义分化、借义分化、同形分化、为双音词造分化字六种类型。并选择典型字例进行分析，包括证明字组的分化关系、分析字组的分工情况两个方面。通过分析具体字例，明确了分化字的出现时代、分化中字词关系的变化等问题。第三章首先讨论了秦系分化字的分化机制，从语言文字内部和当时的社会历史背景两方面探究分化的原因，尝试总结了倾向于构造分化字的义项类型；其次，运用分化字考辨结果考察了一些传世文献的文字释读问题。附录为《秦系分化字表》，字表收集已有前人考察的分化字和本文考察的分化字96个，并呈现文字的用例和相关属性。

The differentiation of Chinese characters is a phenomenon of creating new characters on the basis of the original characters and sharing its function. Differentiation runs through every stage of the development of Chinese characters, and has different features. The Qin characters from the Warring States Period to the Qin Dynasty is a key link in the history of Chinese characters. On the one hand, it is different from the other six states characters, which has obvious regional feature; On the other hand, promoted by Qin Shi Huang's policy of Shu Tong Wen Zi(书同文字), Qin characters became the national standard, which had the status of connecting the preceding and the following. Therefore, it is of great significance to investigate the differentiation of Qin characters.The introduction part briefly describes the significance of the topic, the research program and the existing researches. The ancients had paid attention to the differentiation of characters. The Youwen theory(右文说) and Liushu-xue(六书学) in Song Dynasty, the Fenbie-wen(分別文) of Wang Yun and the Gujin-zi(古今字) of Xu Hao in Qing Dynasty were relevant. In modern times, the theoretical discussion has been deepened and the materials have been expanded, but the differentiation researches based on unearthed documents are scattered, the researches specifically aimed at Qin characters are rare. Therefore, research on the differentiation of Qin characters by unearthed documents is promising.Chapter One explains the relationship between the Qin characters and the other six states characters in the Warring States Period, and divides the Qin characters into two categories: inheritance characters and newly created characters. It makes clear that differentiated character is a type of newly created character, and explains the differences between differentiated character and other relevant concepts. Secondly, it explains how to collect the differentiated characters of Qin, and analyses the data about differentiation modes.Chapter Two divides the differentiation of Qin characters into six types according to the function relationship between mother characters and differentiated characters--original meaning differentiation, derived meaning differentiation, separated meaning differentiation, borrowed meaning differentiation, homographs differentiation and differentiation for disyllabic word. The typical characters are selected for analysis, including proving the differentiation relationship and analyzing the division of characters. The analysis is helpful to clarify the era of differentiation and the change of character-and-word relationship.Chapter Three firstly discusses the mechanism of differentiation in Qin characters, mainly from the language and characters, as well as the social background, and summarizes the sememe types that tend to make differentiated characters. Secondly, we discuss the interpretation of some characters in the handed-down literature.The appendix is Qin Differentiated Characters Table, which collects 96 differentiated characters investigated in previous studies and in this paper. This table also presents the related attributes of the character groups.