Southwestern Mandarin distributes in 9 provinces, including Sichuan, Chongqing, Guizhou, Yunnan, Guangxi, Hubei, Hunan, Shanxi, and Jiangxi. With a population of about 270 million. It is the most widely distributed and populated dialect among Mandarin dialects. The pronunciations are surprisingly consistent (Entering tone of the ancient pronunciation of characters is now read Yangping). The research of dialect researchers mainly focused on phonetics and paid more less attention to grammar. Southwestern Mandarin is the same situation. This paper takes the “Description of Basic Texts of Southwestern Mandarin Chinese” published by the Tokyo Institute of Foreign Languages, Asian and African Languages and Cultures in 1986 as the basic data, also refers to the language data of the BCC corpus, and the suffixes in Southwestern Mandarin “men” and pays attention of comparison of the suffix “Me” in Mandarin Chinese. This paper first indicates the hypothesis that “men” is not only the variant of the diacritical character of “Me” it also has a special meaning in grammar. Secondly analyzes and demonstrates the hypothesis through the “Description of Basic Patterns of Southwestern Mandarin Chinese” and the BCC corpus.