Abstract: The 31 letters from Qin Guan, in which he showed the pain in his heart, narrated the intercourse between his teachers and friends. Moreover, some trivial matters of his daily life were concretely recorded. No matter how long were those letters, they were ‘personal’ writing, Qin Guan naturally showed his innermost authentic feelings in the letters, so they were the precious historical materials for us to comprehensively understand him.