As a common phenomenon in daily or spontaneous conversation，hesitation indicates an elongation or adjustment made by a speaker in order to keep the conversation flow． To communicate successfully does not necessarily mean no hesitation，but how to hesitate and which type of hesitation markers is exploited. Using the seminar section of MICASE as a reference corpus，this study compares hesitation markers occurring in COLSEC and GSSC． Specifically，the classification，the difference of frequencies and the pragmatic fossilization of these hesitation markers are taken into account． Some main findings of this study are( 1) Chinese learners tend to use unfilled pauses and repetitions to hesitate，while native speakers resort to small words to pause or fill gaps; ( 2) Chinese learners have pragmatically fossilized tendency in small words，especially in prefabricated expressions．How to increase pragmatic awareness of hesitation markers in maintaining discourse coherence is crucial in language teaching and second language learning．