China’s annual college enrollment has experienced a significant surge, increasing over nine fold from 1 million in 1998 to more than 9.6 million in 2020 due to a massive expansion initiated in 1999. This paper studies the impact of this expansion on US graduate programs by combining administrative data on Chinese college admission with the SEVIS database on foreign students. Our identification strategy leverages city-year-major variation driven by China's college expansion guided by a quota system, which allows us to control for city-year and major-year confounders. Our estimates imply that the college expansion in China can explain 30% of the rise in Chinese graduate student flow to the US during 2003-2015.