蘇軾一生交友廣闊，李常是他的摯友之一。李常比蘇軾大十歲，但兩人可考的交游時間至少有十八年，他們性情相投，互訴衷腸。由於李常存世的作品較少，因此本文擬從蘇軾的詩詞文作品和其他歷史資料入手，分階段敘述、梳理兩人的交游軌跡，並試圖分析蘇軾與李常交游的深層原因。 兩人在蘇軾的杭州任期內開始慢慢相識，在濟南之行中進一步相互瞭解，在徐州相會中結爲知心友人，在蘇軾貶居黃州期間李常不離不棄，在廬山腳下時蘇軾越發想念摯友，在李常逝世後蘇軾萬分悲痛。綜觀其交游過程，二人結爲摯友之緣由爲：政治上的反對新法，心懷天下，爲政利民。情感上情如兄弟，互相崇慕。二人之情誼真切而珍貴，永爲流傳。

Sushi had many friends during his lifetime, Lichang was one of his best friends. Lichang was ten years older than Sushi and their friendship last at least for eighteen years. Very few of Llichang’work survived now, so I used SuShi's works and other historical information to narrate their story, and also tried to analyze the underlying reasons of SuShi and LiChang’s friendship. They slowly know each other in Hangzhou. They had further understanding of each other during the trip to Jinan and became intimate friends in Xuzhou. Lichang did not abandon Sushi while his was living in exile in Huangzhou, and Sushi missed Lichang so much when he arrived at the foot of Lu mountain and when he heard the death of Lichang.Their friendship was real and precious which will always circulated.