Teacher professional development is the key to improving teacher quality and teaching profession. International organizations and countries around the world have proposed policies, programs, or strategies related to the professional development of teachers. This study employed data from the Teaching and Learning International Survey (TALIS) conducted by the Organization for Economic Cooperation and Development (OECD). Based on TALIS 2018 evidence, it analyzed the landscapes of professional development of teachers in elementary and junior high schools in Taiwan. The research results are as follows. (1) The types of professional development of teachers include thematic seminars, participation in teacher communities, and introduction of educational issues, but less professional learning activities are related to obtaining licenses. (2) The contents of professional development of teachers are subject knowledge, subject teaching knowledge, and curriculum knowledge, and they have less participation in cross-cultural communication and culturally responsive teaching issues. (3) The effects of professional development of teachers are shown in the establishment of professional knowledge, promotion of professional collaboration, and application of teaching practice, but these have failed to promote the sustainable development of the teaching profession. (4) The obstacles to the professional development of teachers mainly come from busy work, insufficient time, lack of incentive, and no appropriate professional development activities. Overall, the professional development of teachers in Taiwan is no less than that in the countries participating in the TALIS survey, but there are still weak points and problems to be overcome. Based on these results, the policy and practice of teacher professional development in Taiwan should help create a cultural climate of teacher collaboration and network connection, and strengthen the cultivation of cross-cultural communication literacy and cultural response teaching competency of teachers. Furthermore, effectiveness evaluation and sustainable development should be emphasized, and support systems for teacher professional development should be built.