The culture of gotong royong needs to be integrated in learning and assessment in schools. Gotong royong culture includes social attitude of respect, cooperation, inclusiveness, commitment to joint decisions, deliberations of consensus, helpful, solidarity, empathy, anti-discrimination, anti-violence, and attitude of volunteerism. In the implementation, many teachers in Indonesia have encountered difficulties in assessment, especially in the attitude domain. To assess social attitudes including gotong royong, researchers developed a model of attitude assessment. This study uses the R & D design (Research and Development) with ADDIE model. First, the researchers created a design in the form of a matrix containing components: determined measurement objectives, described general measurement questions, described required data, determined data resources, determined types of instruments, and determined measurement scale techniques. Second, researchers have developed gotong royong social attitudes assessment which includes self-assessment, peer-assessment, observation guide, interview guide, and journal. The assessment used Likert scale, Guttman scale, differential semantic scale, rating scale, and Thurstone scale for the technique.