This study investigated the characteristics of high-quality mathematics teaching in China following the launch of a new standard curriculum. Data was gathered through video-recorded observations of lessons that won a national teaching contest. We identified and examined the characteristics of the instructional practices through six domains: (1) the mathematics, (2) cognitive demand, (3) classroom management (4) equitable access to mathematical content, (5) agency, authority, and identity, and (6) formative assessment. The results indicated that a well-managed classroom and low level of formative assessment were salient features of the observed lessons. In most cases, though students had a chance to say or explain things, their ideas were not explored or built upon. The majority of the mathematics task designs offered possibilities for "student struggle," but teaching practices tended to "scaffold away" the challenges, which reduced cognitive demand for students. Good mathematics instructional practices are nested in underlying social and cultural values and norms. Implications for practice and future research are presented.