In Chinese, both “danshi” and “dan” are conjunctions which express the meaning of contrast. So far, studies on the usage of “danshi” have been considered from the viewpoints of Etymology (e.g., Li, 2010; Ding, 2010), Semantics (e.g., Zhu, 1982; Lv, 1999; Xing, 2001), Conversation analysis (e.g., Fang, 2000; Yao, 2012) and so on. However, studies on the differences between “danshi” and “dan” are rare and they just analyzed the differences from the viewpoints of Register. Regarding the register, it is observed that “danshi” is significantly more used than “dan” in Spoken Chinese, while in Written Chinese it is reversed (Zhao, 2011, Yao, 2017). In fact, through the daily conversations, we can realize that besides the differences of register, there are many other differences between “danshi” and “dan”. This study aims to use “CCL Corpus” (CCL, Written Chinese) and “Dalian University of Finance and Economics Corpus” (DLUFEC, Spoken Chinese) to clarify the differences between “danshi” and “dan” from the perspectives of the number of occurrences, the position of appearence, the collocation and the conversational function. The result of this study shows that firstly, in Written Chinese, the number of “dan” (16815 cases) is nearly 5 times that of “danshi” (3683 ceses), while in Spoken Chinese, the number of “danshi” (770 cases) is more than 4 times that of “dan” (192 ceses). This result is the same with previous studies' result. Secondly, in Spoken Chinese, both “danshi” and “dan” often occur in the middle of a turn to express contrast, supplement, and maintain the right to speak. They can also occur at the initial position of a turn to change the topic or get the right to speak. In Written Chinese, “danshi” tends to be used to connect two sentences (2073 cases in 3683 cases), while “dan” tends to be used to connect two clauses (12506 cases in 16815
cases). Thirdly, in Spoken Chinese, the percentage of “danshi” used with other conjunctions (4%) is almost the same with that of “dan” (3%). However, in Written Chinese, the percentage of “dan” used with other conjunctions (24%) is higher than that of “danshi” (10%). The most interesting thing is that Lv (1999: 148) believes that there can be a pause after “danshi”, but not after “dan”. However, we found 7 examples of “dan” followed by a pause in CCL. In DLUFEC, there are 20 examples of “dan” followed by a pause. After analyzing the content, we found that this kind of pause plays a role in indicating to the listener or reader in advance that the speaker or the writer will make the opposite or supplementary remarks in the next discourse. At the same time, it also provides time to let the speaker think about what should talk in the following discourse. In a word, a pause can occur either after “danshi” or after “dan” , just the frequency after “dan” is lower than “danshi”. Last but not the least, in Spoken Chinese, the frequency of using “danshi” as a discourse marker (36%) is higher than the frequency of using “dan” as a discourse marker (16%). On the whole, it is clear that although both “danshi” and “dan” are contrastive conjunctions, they do have differences in the position of appearence, the collocation and the conversational function.