The purpose of this study was to develop an instrument to measure the gifted`s task commitment with eye-tracking. Through 21 general students` performing the preliminary tasks, 6 tasks were selected and divided to 3 eye tracking tasks and 3 paper-and-pencil tasks. After other 20 general students performing the tasks, the result was analyzed in equivalent test. Following to the equivalent test, the objectivity of classification and the reliability were analyzed with 17 gifted students. Sequentially, 24 gifted students and 24 general students participated to develop an equation of task commitment in this study. Finally, the developed instrument to measure task commitment was applied to 42 science gifted class students. As a result, the instrument to measure task commitment using classification inquiry is consisted of an eye-tracking tasks and isomorphic paper tasks. Also the equation of task commitment was developed through discriminant analysis procedure. The quotient of task commitment was derived through discriminant analysis using a quantifying method for measuring tasks. The discriminant analysis results showed a significant classification of the gifted from the general students with a 82.4% chance to hit within statistical significant level. In this study, the instrument to measure task commitment could show to analysis not only the difference between gifted group and general group but also the level of task commitment of each person.