Abstract: Languages vary in terms of relative clause (RC) attachment preference. For instance, English is a low attachment language, while German is a high attachment language. This discrepancy affords us an opportunity to investigate the development and transfer of the learners’ syntactic processing strategies. This study, by recruiting Chinese-English bilingual learners and Chinese-English-German trilingual learners as subjects, examined their RC attachment preference in sentence processing. The results indicated that: (1) Bilingual and trilingual learners were sensitive to the meaning of the prepositions (of or with)connecting the two NPs when processing English sentences; (2) Typological distance could influence the cross-linguistic transfer of syntactic ambiguity resolution strategies; (3) Language proficiency was an important factor that affects the development of syntactic ambiguity resolution strategies. This study provides new evidence for the Shallow Structure Hypothesis and discusses the functioning mechanisms of typological difference and language proficiency in the learners’ syntactic ambiguity resolution process.