Mathematics vocabulary (MV) plays a crucial role in learning and understanding mathematics. Beliefs directly impacted teachers’ interactions with the students and implementation of instructional strategies, ultimately shaping students’ learning outcomes. However, there has been a lack of research specifically examining teacher beliefs about MV. This study aimed to investigate teacher beliefs regarding the nature, learning, and teaching of MV through a survey conducted with 234 participants from China. The quantitative results showed teacher beliefs about the nature of MV aligned with existing frameworks, with the exception of polysemy. In terms of beliefs about learning MV, teachers tended to prioritise the knowledge hypothesis. Also, teachers had reservations about learning MV by rote. Regarding beliefs about teaching MV, the majority of teachers agreed with the three teaching modes. These findings provide valuable insights for professional development programmes and offer useful references for improving MV instruction.