Han Yajun started to attend tournaments as arbiter in 2008. With 4 years theory learning and real case experiencing, in 2012 he was awarded the FIDE Arbiter title.
In 2013, when he graduated from college, he decided to pursue his academic study overseas. After graduating from the University of North Carolina at Chapel Hill, School of Education, he chooses to dedicate his work as an arbiter and chess educator.
Awarded with National Instructor in 2016, and International Arbiter in 2017, the youngest IA in China.