Abstract: Northwest China is a place where people of different ethnic groups have converged since time immemorial, so have their languages, in varying degrees, in their historical development. When coming into contact with Chinese, the Manchu language, Japanese and Russian all made far-reaching impact on the formation of Northwestern Mandarin. In more than 296 local chronicles of administrative divisions above county level, more than 5800 dialect words are recorded. Sorting out these words, analyzing them with theories of contact linguistics, exploring formation and development of Northwestern Mandarin, and conducting comparative study on Northwestern Mandarin, Mandarin Chinese and languages of other ethnic groups – all these efforts can make a big difference on the study of formation and causes of contact phenomena of modern Chinese.

Key words: local chronicle, dialect of Northwest China, theory of contact linguistics