Book reading enhances the intellectual world of people. It is very important to know the factors that motivate children to read books as it will help to instill book reading habit in them. As such, the present study aims to develop a "Book Reading Motivation Scale" to determine elementary and secondary school students' reading motivation. First, a draft scale consisting of 25 items was constructed. Reliability and validity study of the scale was conducted on the data collected from 1224 elementary and secondary school students. In the first stage, exploratory factor analysis was carried out and discrimination power of the scale items was detected. As a result of the exploratory factor analysis, it was found that the scale comprised two sub-dimensions called "love for reading" and "reason for reading." Previously, confirmatory factor analysis (CFA) had been run to test the construct validity of the scale. As a result of this analysis conducted through AMOS program, it was found that goodness of fit coefficients were within the acceptable limits. At the end of the study, a scale consisting of 14 items that can explain 46.292 of the total variance was obtained. Internal consistency coefficient sum calculated by means of Cronbach Alpha method to determine the reliability of the scale is a = 0.85. In order to reveal item discrimination of the scale and the extent to which the items can predict the total score, 27% bottom-top group comparisons were made. As a result, a questionnaire form that has reliability and validity in the analysis of elementary and secondary school students' book reading motivation was developed. It is hoped that Book Reading Motivation Scale (SMRB) can bring a new dimension to the research in the field of reading, and as a useful tool to teachers wanting to motivate their students to read.