This study examined and compared the intended mathematics curricula according to topic coverage, focus, coherence, and learning progression in grades 1-12 within China and the province of Ontario, Canada. The findings show that the overall topics in the two curricula are similar: Chinese curriculum covers 78 topics out of 79 while the Ontario curriculum covers 76. The two curricula also share a similar general sequence such as topics for transfer stages from numbers to functions by starting with constant mathematics, then variable mathematics, and finally functions. However, the detailed topic design of the 2 curricula differs markedly. The Chinese curriculum includes few topics in each year, a short duration or span of each topic, and a fast-paced topic progression. The Ontario curriculum, in contrast, includes more topics each year, longer duration of many topics, and a small pace of topic progression in grades 1-8 and a fast pace of topic progression in grades 9-12. Because of different curriculum designs in grades 1-12, the intended curriculum may influence students' cognitive structures of mathematics, learning behavior and thinking, learning efficiency and achievement, and teachers' professional development. This calls for more refined and advanced research on the defined list of topics, topic organization, and terms to study curriculum in order to increase student learning opportunities.