This research aimed at developing locus of control scale for high school students. To achieve the purpose of the study, 59 items were written according to a Likert rating scale forming the preliminary scale. The responses of 768 high school students were analyzed using the Muraki Rating Scale Model. The results of the analysis indicated that 47 items not only fit the expectations of the model, but also they cover locus of control trait systematically and have appropriate psychometric properties with a reliability coefficient of 0.93 and several validity indicators. The results also showed that the items of the scale yielded high discrimination, which made these items contribute in offering the maximum amount of the information about the relative position of the students on the locus of control trait.