The current study aimed to construct a questionnaire that measures students' personality traits related to "striving for understanding" and "learning value of geometry" and then examine its psychometric properties. Through the use of multiple methods on two independent samples of 402 and 521 middle school students, two studies were performed to address this issue to provide support for its validity. In Study 1, exploratory factor analysis indicated the two-factor model. In Study 2, confirmatory factor analysis indicated the better fit of two-factor model compared to one or three-factor model. Convergent and discriminant validity evidence provided insight into the distinctiveness of the two factors. Subgroup validity evidence revealed gender differences for "striving for understanding geometry" trait favouring girls and grade level differences for "learning value of geometry" trait favouring the sixth- and seventh-grade students. Predictive validity evidence demonstrated that the "striving for understanding geometry" trait but not "learning value of geometry" trait was significantly correlated with prior mathematics achievement. In both studies, each factor and the entire questionnaire showed satisfactory reliability. In conclusion, the questionnaire was psychometrically sound.