This study aims to help grammar teaching based on discourse speech act for Polish learners of Korean language by examining the aspects of refusal speech act among Polish learners of Korean language, native Korean speakers, and native Polish speakers. Refusal speech act is a response speech to suggestion, demand, invitation, and request from other people and it becomes face-threatening act to the other party of dialogue therefore, verbal and non-verbal strategies are required for speaker to protect the face of the other party of dialogue and to mitigate the burden of speaker thereby. Therefore, foreign learners need to learn social customs that the members of target language society share in order to use such strategies properly. It is especially important to understand and accept the politeness soaked into Korean language and culture. This study found that Polish learners of Korean language prefer using direct refusal strategy. In order to minimize the face-threatening act to the other party of dialogue upon using direct refusal strategy, moreover, they use various indirect strategies together so that their average frequency of strategy use for refusal quite higher than that of native Korean speakers group and native Polish speakers group. In addition, it can be inferred that this is related with their uneasiness for imperfect use of Korean language under development as learners of foreign language. On the other hand, Korean group was found to prefer using indirect refusal strategy and also prefer using euphemistic expression than negative expression even when they use direct refusal strategy, which tells us that Polish learners of Korean language need to be educated with social and cultural customs and values of Korea. (Kyung Hee University)