The primary purpose of this study is to test the Interlanguage Structural Conformity Hypothesis (ISCH) which predicts that implicational universals also influence the structuring of interlanguage phonology. L2 learners will modify more marked structures more frequently than less marked structures. How do Chinese ESL learners deal with tri- and bi-consonant onset clusters, since no consonant clusters are licensed in Chinese? Nine subjects of Chinese native speakers in Taiwan were asked to read sentences and words containing onset clusters. Results indicate that Chinese subjects tended to alter the more marked, tri-consonant clusters, more frequently than the less marked, bi-consonant clusters. Between the two bi-consonant clusters, we also further proved that Minimal Sonority Distance may be inadequate to be a viable construct for determining the markedness of consonant clusters in the onset of a syllable.