Driven by the Principle of Economy in language use, the Chinese structure “非(Fei) X 不(Bu) Y” has shifted from the two mere negative words “非(Fei)” and “不(Bu)” into a fixed language structure, which not only embodies the emphasis on both subjective and objective emotional color on the semantic level, but also meets the standard of grammaticalization. When interpreting this structure, “X” and “Y” play a vital importance in the sentence meaning.