This study, based on the data from PhD dissertation (and proposal) defences, investigates the use of epistemic stance markers “wo xiang”(I think),“wo renwei”(I think),“wo juede”(I feel)and “wo ganjue”(I feel)and their variants in academic interaction in the Chinese context. It is found that these markers are used by committee members in the two types of defence interaction with a similar tendency except “wo renwei”. “Wo juede” and its variants occur with a much higher frequency than “wo xiang”,“wo ganjue” and their variants in each type of defence interaction; “wo renwei”,with a very low frequency, occurs only in PhD dissertation defences. Eight pragmatic functions can be performed by these markers in academic interaction and obvious differences exist between the two types of defence interaction in the occurrence of these pragmatic functions. In addition, differences can also be observed in the categories of pragmatic functions respectively performed by the four markers and their variants.