Abstract: The influence of frequency on L2 construction acquisition and processing has received much attention.However, few studies have considered its influence on the L2 processing of mismatch constructions such as Light Verb Constructions (LVC).The present research addresses the problem through ERP experiments on native speakers and high-proficiency Chinese ESL learners.Significant frequency effects are found in both groups, though at different points and with different ERP components.Native speakers show N400 at the final word of the low-frequency LVC, while delayed effects are found in the learner group at the preposition/particle following the LVC (N400) and at the sentence-ending noun phrase (late sustained negativity).The results suggest that construction frequency, form-meaning mismatch and their interaction influence the processing of LVC in both groups.They also result in an unbalanced representation of construction schema in the learners, where the construction form is better represented than the meaning.The findings support the usage-based construction acquisition approach.