In recent years, developing language assessment literacy (LAL) has become crucial for teachers in enhancing their teaching practices and improving students’ learning outcomes. Empirical research reported that there was a training need for formal education and professional development programs in assessment (Berry et al., 2017; Vogt & Tsagari, 2014). Therefore, this paper reports a systematic review of teachers’ language assessment literacy development: training needs, training effective factors, and language assessment practice constraints. The purpose of the review is to provide an updated overview of the empirical research on language assessment development. I utilized systematic review for social studies using the following steps: forming research questions, choosing the appropriate search terms and strategy, starting the literature search, developing inclusion criteria, determining relevant studies, and extracting data (Petticrew & Roberts, 2006). The search was limited to the 12 years’ publications because there was an increase attention on developing teacher’s language assessment literacy in these years. The selected studies were analyzed using the content analysis approach. The results suggested that teachers needed in-service training in different LAL content areas that varied according to the educational context needs in their countries. The results also revealed that teachers' experience and self-reflection needed to be considered in development programs and teachers should be involved in collaborative learning communities. The collaborative learning communities provided the needed professional support and give the chance for teachers to share their experience. Furthermore, the reality and constraints needed to be recognized as they influenced teachers' assessment practices. Finally, research implications and future research directions on teachers’ language assessment literacy are discussed.