Internal assessment is an integral part of teaching and learning in Social Studies in the Colleges of Education and is beneficial to both students and tutors if use formatively. It is therefore important for teachers to have positive conceptions towards formative assessment in order to win back public confidence. This could be achieved if, tutors try to follow the laid down procedures in administering formative assessment in their colleges. There is therefore the need conducting a study into tutors' conceptions of formative assessment and how they apply it in their instruction. The study adopted a case study research design. The study was carried out in three Colleges of Education. The data were used together to form one case. Both the Tutors and the Colleges were purposively and conveniently selected for the study. The study used two instrument for the data collection, namely interview guide and classroom observation.