There are several demonstratives in Archaic Chinese which are later grammaticalized to various grammatical markers. Distal demonstrative “FU(夫)” is the historic source for introductory particle, named “FAYUCI(發語詞)”. “FU” has demonstrative function and FAYUCI function simultaneously until the Han dynasty, but since the Wei, Jin dynasties, “FU” only has FAYUCI function. After the Song dynasty, “FU” finally disappeared in the history. The grammaticalization and extinction of “FU” result from its weak reference feature. Its reference feature is weaker than “BI(彼)” which also belongs to the distal demonstratives, and this is why “FU” became lose their reference function and finally disappeared.