Comparison is an essential cognition process of human kind. It is the internal motivation to generate various comparison categories. In 1898, Ma Jianzhong published his famous work Ma's WenTong, which started the study of the category of comparison. However, compared with the studies in other categories, the study in the category of comparison is still weak. This thesis is divided into nine chapters. In the Introduction (Chapter 1), the author presented the significance of this study, research methods as well as language materials resources. The overall study in this PhD work was concluded in Chapter 9. Besides these two chapters, the rest content of this thesis is made up of two sections. Section 1 includes 3 chapters, whereas Section 2 includes 4 chapters, which is specified as follows: Section 1: Systematic Study on the Category of Comparison The Chapter 2 is on the study of category of superiority. The Chapter 3 is about the study on the category of equality. According to nature and function of "W", which exist in sentence structure "X is Wer than Y", Chapter 4 presented the study on the category of superlative. Section 2: Specific Sentence Structures in the Category of Comparison Chapter 5 is on the study of the sentence structure "X is W er than Y". Chapter 6 is on the study of the sentence structure "Not as". The research on particular sentence structures is presented in Chapter 7. Chapter 8 is the study on the topic comparison sentence.