Taiwan has actively taken actions to support the aim of UNESCO's ESD (Education for Sustainable Development) for 2030 as well as SDGs (Sustainable Development Goals), and has to face and solve some emerging challenges that come with progress. This paper firstly introduces the status of STEM-related ESD/SDG Activities, and identifies the following five new challenges in teaching materials for STEM-related ESD/SDG activities: (1) Teachers are not familiar enough with teaching materials in non-specialized fields in cross-field STEM-related ESD/SDG activities; (2) Teachers need to spend too much time transforming ready-made social resources; (3) The ability of primary and secondary school teachers and students to use international teaching materials is often limited due to their language skills; (4) Lack of a comprehensive platform for exchange and sharing of teaching materials; and (5) The COVID-19 pandemic caused emergency remote teaching which suffered from limited quality online teaching materials.