This study aims to explore constructs of grammar inquiry. For this purpose, the self-awareness of learner about grammar inquiry ability has been surveyed and exploratory factor analysis was conducted. According to the result, `problem finding` could be established as one factor, but `establishing a hypothesis`, `verifying a hypothesis`, `drawing a conclusion` are combined into one factor, and `generalization`, `monitoring and regulation` are also combined into one factor. The result implies that `analytical ability` could exist on the base of `establishing a hypothesis`, `verifying a hypothesis`, and `drawing a conclusion`. Also, `metacognitive monitoring of the inquiry process` could be established as one factor, because metacognitive ability could exist on the base of `generalization` and `monitoring and regulation`. The result also implies that while the sort of grammatical knowledge is involved in grammar inquiry process, but whether the knowledge is about structure or about semantic function is irrelevant to the factor. Finally this study suggested that more researches on constructs of grammar inquiry should be conducted by using qualitative and quantitative methods, because constructs of grammar inquiry can not be determined through just one study.