This study analyzes the discourse function of the modern Chinese response word "zhidaole(知道了)". When using "zhidaole", the relationship between the speaker and the listener needs to be considered. It applies to the elders to the juniors, the boss to the subordinates, and occasionally the response between the peers, but it applies to the responses of the subordinates to the boss and the juniors to the elders. In addition, it can not only express a simple response function, but also mean "the listener has fully understood the facts, and the speaker does not need to explain too much", and it also has the function of discourse termination. The speaker does not want to do too much discussion about the topic the other party is talking about, forcibly end the topic, or change the topic. The Korean words "알겠습니다" and "알았어요" also express multiple discourse functions. There is no correspondence between the Chinese "zhidaole" and the Korean "알겠습니다". The Korean "알겠습니다" expresses a respectful attitude, a respectful way of acting in accordance with the request or instructions of the other party. The meaning of "알았어요" in Korean is closer to the Chinese "zhidaole". Both have the function of ending discourse. Therefore, when Korean students are learning Chinese, they should avoid corresponding "알겠습니다" to "zhidaole" to avoid language misunderstanding and impolite manners.