Researchers in teacher education have suggested that many of teachers classroom decision-making and actions are based on some sort of theoretical framework which are beliefs driven (Armour-Thomas, 1989; Clark & Peterson, 1986; Marland, 1995, 1998). Such beliefs driven theoretical framework constitute teacher's conceptions about teaching and learning and build up their principles of classroom practice. These beliefs or theoretical frameworks are given various labels in literature including implicit theories or personal theories about teaching and learning. Studies of teacher's personal theories are often conducted by means of qualitative methods such as interview, narratives and analysis of reflective journal about teaching. Quantitative measure by means of questionnaire or inventory to study personal theories are few but they are useful to provide a global picture or profiles of teachers beliefs/conceptions about teaching and learning. This paper attempts to develop and validate an instrument to measure teacher's personal theories. By means of which teacher educators and teacher education students can have an understanding of student teachers beliefs and conceptions about teaching and learning, which is considered a functional way of helping them learn how to teach in their course of professional development. Thus the validated measure assists teacher educators to evaluate the effectiveness of the teacher education program with reference to the identified profile of personal theories of their students. Also, the relations of demographic variables of teacher education students and their personal theories were analysed to investigate if there is any influence of age, gender and electives studied on the students beliefs or personal theories about teaching/learning, based on which implications and suggestions are drawn for teaching education development and research.[Copyright of Australian Association for Research in Education (AARE) at http://www.aare.edu.au]