Using an acceptability judgment task of overgeneralized instances of the caused-motion construction, the present study investigates the influences of entrenching frequency, preempting frequency and L2 proficiency on Chinese EFL learners’ argument structure overgeneralizations. The results indicate that 1) there is no independent entrenching effect in overgeneralizations, 2) the preempting effect is relatively strong, but it conflicts with the Preemption Hypothesis in terms of the effect direction and is intensified by entrenching frequency,3) the acceptability is judged relatively high in general, especially by the advanced learners. Such results are attributed to that 1) there exists a theoretical defect in the Entrenchment Hypothesis, 2) L2 learners lack of both basic prerequisites for the preempting mechanism and they only focus on the semantic associations but not on the distinctions between the preempting-overgeneralized structure pairs, 3) while the awareness of the semantic associations is raised as their language proficiency increases.