When Liangshan Marsh is first mentioned in Water Margin, it is occupied by bandits led by Wang Lun, Du Qian and Song Wan.

Song Wan, along with Wang Lun and Du Qian, is first mentioned when the nobleman Chai Jin suggests to the former imperial troops instructor Lin Chong, who has killed three men sent by Grand Marshal Gao Qiu to murder him in Cangzhou, that he could take refuge in Liangshan.

But Du Qian, Song Wan and Zhu Gui, who runs an outlying inn which acts as a lookout for Liangshan, plead on Lin's behalf.

Later Chao Gai and his six robber friends, wanted for hijacking valuables in transportation to Grand Tutor Cai Jing in the imperial capital Dongjing, seeks refuge in Liangshan.

In the battle of Runzhou (潤州; in present-day Zhenjiang, Jiangsu) in the campaign against Fang La, Song Wan falls from an arrow shot and is trampled to death by the enemy cavalry.