Although Mandarin Chinese is shared by Chinese communities such as Mainland China, Taiwan, Hong Kong and Singapore, linguistic differences are frequently found among regional uses, ranging from pronunciation, orthography, vocabulary, grammar and discourse. Along with the increasingly recognized notion of “World Chineses” in recent years, the study of regional variations has also become more linguistically, socially and culturally significant. With specific examples of the linguistic features exhibited in Mainland China, Taiwan, Hong Kong and Singapore Mandarin Chinese, this chapter will provide an overview of the current studies, methodologies and motivations pertaining to these variations.