This study discusses “Ya” and “Chi”, two Chinese morphemes found in the Contemporary Chinese Dictionary that are difficult to distinguish in daily usage. In order to better understand the difference between them, the study employs the perspective of cognitive linguistics to analyze the structures and semantics of words made of “Ya” and “Chi”. The results of this analysis point to several conclusions. Most words composed of “Ya” and “Chi” are nouns, and most compound words that include them are of the “modifier-head” type. Words composed of these morphemes, moreover, demonstrate a expansion in meaning: in addition to their original meaning, some of these words have also accrued new meanings, primarily through metaphor and metonymy.