Overshadowing refers to the reduced learning or expression of the association between a weaker cue and an outcome in the presence of another stronger cue. The present study broadens the scope of investigation in second language acquisition (SLA), which has mainly focused on inflectional morphology, by extending it to learning two Chinese syntactic constructions, namely the Ba-construction and its SVO counterpart. Thirty L2 Chinese learners were first exposed to the target constructions via watching videos, and were then tested for comprehension and production. The results were three-fold: first and foremost, they yielded evidence of syntactic overshadowing of the Ba-construction by its SVO counterpart, resulting in the reduction of the quantity and quality of the Ba production; second, since the form-meaning mapping was successful for both the Ba and SVO construction, the syntactic overshadowing is more likely to be an expression deficit; and third, the pre-knowledge of verbs further confined the use of the Ba-construction, suggesting a moderating role of word entrenchment in L2 syntactic learning. These findings not only deepen our understanding of overshadowing at the syntactic level, but also offer a fresh perspective for addressing the challenges of L2 learning of the Chinese Ba-construction.