Redox reaction is an important concept in chemistry, and a well-organized knowledge structure of redox reaction is beneficial for concept learning. This study investigated the knowledge structure regarding redox reaction from 459 Grade 10 students. The pool of 15 redox reaction concepts was developed by content analysis, questionnaire survey, and interview. Six initial competing models with 15 concepts were identified via exploratory factor analysis (EFA) and paper-pencil test. Confirmatory factor analysis (CFA) was conducted to test and modify the six competing models according to the rating data of the students. As a result, six modified models fit the data well. However, the high inter-factor correlations indicate that the two- and three-factor models are the students' knowledge structures of redox reaction. The two-factor model is comprised of two distinct but correlated factors: the process of redox reaction and metrology. The three-factor model is comprised of three factors: the process of redox reaction, reaction ability, and metrology. The finding inflects the abstract relationships between the concepts related to redox reaction in students' minds.