Re-examination of Chen San's hometown in Southern Song Dynasty is an academic paper. Chen San in the Southern Song Dynasty refers to Chen Yaosou, son of Chen Shenghua in the Northern Song Dynasty, (in the second year of Emperor Taizong's reign (989), Chen Yaozuo (in the second year of Emperor Taizong's reign (988), a scholar, and a prime minister), and Chen Yaozi (in the third year of Emperor Zhenzong's reign (1000). They are all from Langzhou (now Langzhong, Sichuan).