Technological pedagogical knowledge is quite a serious issue and is a problem today. This is based on conditions in the field which show that not all teachers are well prepared with this knowledge. This study aims to empirically find factors that influence the technological and pedagogical knowledge of prospective professional teachers in elementary schools. This research is survey research using a quantitative approach. This research design uses a structural equation model. This design involves four variables, namely content knowledge, technological knowledge, pedagogical knowledge and technological and pedagogical knowledge. The subjects of this research were participants in professional teacher education in Indonesia. The sample participants for this study were randomly selected as many as 151 participants. The data collection technique for this research was carried out using a questionnaire. The research instrument measures four variables using 12 measuring items which are indicators for variable measurement. Data were analyzed by structural equation model. The research results show that an important factor that has a dominant effect on the formation of teachers' technological pedagogical knowledge is good technological knowledge. In addition, pedagogical knowledge is also one of the triggers for technological pedagogy knowledge. Although based on empirical findings, the influence of this knowledge is not as great as technological knowledge. Furthermore, the factor of technological pedagogical knowledge is also indirectly shown in the content knowledge variable. The findings of this study explain that there is a fairly strong indirect effect.