Multidimensional (MD) analysis contributes to a comprehensive linguistic description of second language (L2) writing texts. However, cross-linguistic studies based on MD analysis are still insufficient and need to be increased. In particular, the unavailability of comparable corpora prevents current MD-based L2 writing research from making reliable comparisons of linguistic differences between native writers and L2 learners. Considering these, this study adopts corpora of maximum similarity for the cross-linguistic comparative analysis. Using Biber's MD analysis, this study compares linguistic differences between native English writers and Chinese English learners in argumentative essays with similar communicative purposes. The analysis reveals that the two groups of texts show significant differences in slightly over half of the individual linguistic features but share more similarities than differences in textual dimensions. It also shows that the two groups are, in fact, different varieties of English language use, even though they share a similar text type of "involved persuasion." The results confirm the importance of comparable corpora for cross-linguistic comparisons and the necessity of MD analysis for understanding L2 writing.