This paper investigates the syntax and semantics of the scalar particle HAI combined with Chinese bi comparatives. Several empirical facts are presented and discussed. First of all, two syntactic positions of HAI are identified: syntactically, the scalar particle HAI can either precede the comparative standard (HAIhigh) or follow it (HAIlow) in the Chinese bi comparative. Second, HAIlow leads to a positive inference while HAIhigh does not. Third, although many focus particles may appear in the position of HAIhigh, they are categorically banned from the position of HAIlow. Finally, HAIhigh conveys that the assertive content contravenes the speaker’s expectation. The core proposal made in this paper is the following. Syntactically, HAIhigh is an adjunct adjoined to the degree phrase while HAIlow occupies the degree head. Semantically, the scalar HAI involves two core ingredients: a scale and some presuppositional conditions based on the type of the scale. In particular, HAIhigh employs the scale of likelihood (similar to English even) and presupposes that the prejacent p is less likely than its alternative ¬p: the negation of the prejacent. By contrast, HAIlow takes the scale provided by gradable predicates and presupposes that both the comparative target and the comparative standard are ordered above the contextual standard of the scale. Finally, it is proposed that the semantics of the scalar HAI is constrained by its syntactic position: while HAIhigh operates on the domain of propositions based on the scale of likelihood, HAIlow on the domain of degrees based on the dimension of gradable predicates.