In the knowledge-based society, education is undergoing widespread reform in many school systems worldwide. One of them is to focus upon the preparation of pre- and in-service teacher's teaching methods with information and communication technologies (ICTs) in the school curriculum. The purpose of the present study was to explore the theoretical backgrounds of teacher's core competencies for utilizing ICTs in the knowledge-based society. Based upon a literature review, six domains for developing teacher's core competencies in the field of information technology in teacher education (ITTE) were identified as follows: (a) Basic skills on computer and Internet; (b) Teaching psychology and instructional design; (c) Design, development, and utilization of ICTs for effective teaching and learning; (d) Integration of ICT's utilization into subject; (e) Understanding virtual community and distance education; and (f) Cross-cultural understanding and ethical issues for information management. Basic knowledge and skills for ITTE could give teachers at least some opportunity to develop core competencies to develop and utilize ICTs in the classroom effectively . In this paper, it is shown that the change in the process of teaching and learning can come about with teachers' competence for the utilization of ICTs in knowledge-based society.