Abstract:" Ban GeNP" is a polysemantic construction that can express both objective measures and subjective perceptions, with a series of formal differences. Past research has focused only on objective measures, with little attention to subjective perceptions. This paper explores the cognitive basis for the subjective semantics of " Ban GeNP" based on construction grammar and the categorization theory of cognitive linguistics. The paper holds that the subjective NP highlights perceptual attributes and has prototype effects, which is different from the objective NP that highlight measures and references. The constructional meaning of " Ban GeNP" can be summarized as "the category membership of the object is between the NP and non-NP", that is to say, the object is a peripheral member of the NP category. From objective measures to subjective perceptions is a process of constructionalization, involving mechanisms of subjectification and categorization. The paper also finds that the ability to categorize peripheral members is our general cognitive ability and that English and Chinese have an inherent cognitive consistency.