Objective: The present study was an attempt in order to explore the effect of applying lexical equivalent corpus on Iranian translator trainees' achievement in the translation of compound-complex sentences. Methodology: To perform this, some Iranian translator trainees were selected to participate in this research study. In order to evaluate the translator trainees' achievement in the translation of compound-complex sentences, the researcher asked the participants to fill out a questionnaire. Results: After that, the raw data were collected and analyzed through appropriate statistical tests. Conclusion: Obtained results revealed that applying lexical equivalent corpus did have significant effect on Iranian translator trainees' achievement in the translation of compound-complex sentences.
