LI Jinsong, a Beijing Municipal Special-Grade Mathematics Teacher, a municipal mathematics subject leader, and an Outstanding Contributor at Tsinghua University. He is a core member of the editorial team for the People’s Education Press (Version B) mathematics textbooks and teacher’s guides, and serves as Deputy Team Leader for the "Research on Mathematical Modeling Practice in Primary and Secondary Schools" project under the Institute of Curriculum and Textbook Research, Ministry of Education, P.R. China (ICTR). He is Executive Council Member of the Tsien Excellence in Engineering Program - Secondary School Top Talent Cultivation Alliance, part-time teaching researcher of Haidian District, mentor of the Haidian District Famous Teacher Workstation, and trainer for new teachers in the Haidian District. He has published over ten professional monographs, and has served as a homeroom teacher for ten years and grade level leader for another ten years. The classes he has led have been recognized three times as Outstanding Class Collectives of Beijing, and the grades under his leadership have received the Advanced Collective Award from Tsinghua University three times. He has been named "Outstanding Young Teacher in the Haidian District Education System" three times, "Exemplary Four-Virtue Teacher in the Haidian District Education System" five times, has twice received the Qidi Award for Outstanding Achievement, and was awarded the inaugural Fenghua Cup Principal’s Award at THUHS.