This is a detailed fieldwork-based study of Salar, a mixed, unwritten language of Turkic origin spoken in Northwestern China. Due to its geographic isolation it has become an important object of research for language contact and creolization, since both its dialects have diverged sharply under the influence of Sino-Tibetan and other Turkic languages, incorporating many Chinese and Tibetan elements. The work emphasizes diachrony, and contains an overview of the origins and history of the Salars and their language. The phonemic inventory, synchronic and diachronic phonology, syllable structure, and areal features (obstruent voicing and consonantal preaspiration) are presented and analyzed.