In modern Chinese, an object can precede or follow a quantifier (numeral + verbal classifier) when they co-occur after a verb, which is supposedly affected by multiple factors. Within a usage-based probabilistic variationist framework, this study defines the above ordering as the alternation of the Event-quantifying Construction and examines ten potential variables that probabilistically constrain the construction alternation, using three multivariate methods. Results indicated that six variables significantly affect the selection of the two variants, i.e., "Quantifier-first construction" and "Object-first construction", including the animacy, definiteness, givenness, and pronominality of objects, as well as the length difference between objects and quantifiers and the type of verbal classifiers. The two variants differ in the values of these variables, which may result from the postverbal constraint, the end-focus principle, and the end-weight principle in Chinese. However, these distinctions in the formal or semantic aspects will be neutralized in natural communication, thereby allowing the alternation of this construction.