Critical thinking in writing for learners is needed to able to build a sense of crisis towards any issues. This capacity is required to create a framework based on reflecting, exploring, and solving some practical problems in their learning, work, and daily lives. This article aims to enhance critical writing towards undergraduate students in conducting research. The research method used is descriptive method with qualitative approach. The data used to analyze is gotten from many research articles in international journals discussing critical writing to conduct a research proposal. The research discussion and result state that learners' capacity to be familiar with critical thinking writing is essential. It deals with brainstorming the problems of research topics, reflecting, and exploring the issues of research topics. Students should also have the capacity to write the research background, research problem, review of related literature, and research method based on the guidelines of the research proposal. The writing skill relating to the competence of organization, elaborating content, paying attention mechanics, language use, and vocabulary become the leading and supporting capital to be successful in conducting the research proposal.