In this essay, I investigate how Chinese Yogācāra scholars of the Tang 唐 dynasty explicated and supplemented the theory of apoha (exclusion) propounded by the Indian Buddhist epistemologist Dignāga 陳那, according to which a nominal word functions by excluding everything other than its own referent. I first present a brief exposition of the theory. Then, I show that although they had very limited access to Dignāga’s theory, Kuiji 窺基 and Shentai 神泰 provide constructive and significant explanations that supplement the theory. I also show that the term zhequan 遮詮 (excluding expression) has been construed in Chinese Buddhism in at least three different senses to mean: (1) an expression that both excludes and signifies, (2) an expression that merely excludes and does not signify, and (3) a negative expression that merely excludes. The notion of apoha is related to the first two senses but not the third.