An ongoing debate in Chinese psycholinguistics is whether subject-relative clauses or object-relative clauses are more difficult to process. The current study asks what happens when structure and plausibility are pitted against each other in Chinese relative clause processing. Chinese relative clause structures and semantic plausibility were manipulated to create both plausible and implausible versions of subject- and object-relative clauses. This method has been used in other languages (e.g., English) to elicit thematic role reversal comprehension errors. Importantly, these errors—as well as online processing difficulties—are especially frequent in implausible versions of dispreferred (noncanoncial) structures. If one relative clause structure in Chinese is highly dispreferred, the structural factor and plausibility factor should interact additively. If, however, the structures are relatively equally difficult to process, then there should be only a main effect of plausibility. Sentence reading times as well as analyses on lexical interest areas revealed that Chinese readers used plausibility information almost exclusively when reading the sentences. Relative clause structure had no online effect and small but consistent offline effects. Taken together, the results support a slight preference in offline comprehension for Chinese subject-relative clauses, as well as a central role for semantic plausibility, which appears to be the dominant factor in online processing and a strong determinant of offline comprehension.