Abstract: Conceptual transfer is a new research trend in the field of language transfer, yet previous studies mostly based their analyses on the linguistic level rather than the conceptual level. Moreover, the bi-directionality of conceptual transfer has been seldom touched upon. Targeting the conceptual domain of motion events, this study investigated the expressions and conceptual schemas of motion events of low- and high-proficiency EFL learners and compared them with native speakers of Chinese and English with the data collected from two tasks (i.e. a story retelling task and a similarity judgment task using E-Prime), to explore whether bidirectional conceptual transfer exists and how it is related to L2 proficiency. The results show that 1) Chinese EFL learners underwent bi-directional conceptual transfer, evidenced by their expressions and conceptual schemas of motion events different from native speakers of Chinese and English; 2) expressions and conceptual schemas of motion events of low-proficiency EFL learners were closer to those of native Chinese speakers while those of high-proficiency learners more approximate to native English speakers. This seems to suggest that the higher the English proficiency, the less prominent the forward transfer and the more prominent the backward transfer.