Bawang dialect is spoken in Dpa’dbang Township and Nyaga Township of Rongbrag County, Dkarmdzes Prefecture, Sichuan Province; it belongs to Central Horpa, under Horpic cluster, Rgyalrongic subgroup, Qiangic Branch, Sino-Tibetan Family. For the first time, the present thesis describes the grammar of Bawang in depth with firsthand fieldwork data, focusing mainly on tense-aspect, evidentiality, mood and modality. Chapter 1 introduces the motivation and methodology of the study, and reviews previous literature. As a historical background, Chapter 2 recapitulate the term “Hor(pa)” from the diachronic perspective, as well as the term “Rgyalrong,” with which the Bawang people identify themselves. In addition, the modern history of Rongbrag and Dpa’dbang is briefly summarized. The phonology of Bawang is elaborated in Chapter 3, in order to provide prerequisite knowledge for the following linguistic description. The structures of consonant clusters in the onset and the combinations of vowels and codas in the rhyme are discussed exhaustively, and the marginal suprasegmental feature is also mentioned. The main topic of Chapter 4 is the morphology of noun, pronoun and verb in Bawang, but two important types of clitics, i.e. the number marker and the case marker, are included as well. Chapter 5 accounts for tense-aspect. Based on the findings of Tian & Sun (2019), the author expounds thoroughly the functions of relevant affixes and auxiliaries in Bawang. With respect to tense, since past imperfective and non-past imperfective are distinguished formally, Bawang is a tensed language in principle. As for aspect, one of the characteristics of Bawang is the completely preserved suppletive paradigm of aspectual distinctions for the orientationally specified motion verbs. Chapter 6 focuses on evidentiality. There are three evidential suffixes in Bawang, i.e. hindsight, immediate and past direct. Besides the basic function of these markers, the interaction between evidentilaity and tense-aspect is also touched. Chapter 7 deals with modality, and the content is divided into two main parts, that is, moods and modal suffixes. For the former, the declarative, the interrogative and the irrealis are discussed; for the latter, five modal suffixes and the constructions where they appear are introduced. Concluding remarks and future prospect are given in Chapter 8.