Teacher cognition is seen as an important factor for the quality of instruction and, accordingly, student learning of a subject. However, in-depth research on these relations can only be done if a sound theoretical model for subject-specific teacher cognition (knowledge and competence/practical skills) and corresponding measures are available. This work aims at the development of reliable and valid measures for primary school teachers in mathematics. The subject-specific cognition is modeled as basic professional knowledge (BK) and further two components of reflective competence (RC) and action-related competence (AC). Using video-based items, we developed a computer-based standardized test and collected data of N = 85 primary mathematics teachers. We present results on the quality of the measures and have a closer look on the structure of teacher cognition. [For the complete proceedings, see ED597799.]