In recent years, there has been a growing interest and concern in the role of collective intelligence in education contexts; however, the collective intelligence has been hardly measured. The purpose of this study was to develop and validate the collective intelligence scale which measured the students' collective intelligence in university classes. In study 1, collective intelligence scale was developed and tested for its factor structure, reliability, and validity. Data were collected from 748 students at A university and H university. Both exploratory factor analysis and confirmatory factor analysis were employed with the data from the two universities to find the dimension of the construct of the scale and to test its construct validity. As a result, 15-items were determined for the collective intelligence scale and the third dimensions of collective intelligence were included: cognitive exploration (4 items), cognitive collaboration(5 items), collective integration (6 items). The purpose of study 2 was to examine the structural relationship among collective intelligence related variables in order to validate the collective intelligence scale. Data were collected from 277 students at A university, G university and H university. The collected data was analyzed by using structural equations modeling. It turned out that team trust and team efficacy influenced collective intelligence positively. These findings offer theoretical background and practical implications for collective intelligence in academic settings.