The novel depicts Chai Jin as handsome-looking with eyebrows like those of a dragon, eyes like those of a fenghuang, red lips and white teeth.

According to Water Margin, Zhao Kuangyin felt guilty about the usurpation so he treated the Chai clan well, granting them many privileges which were later passed on to their descendants.

Fairly good in martial arts, Chai is known to open his doors to all chivalrous men and will provide them generously with money when they leave.

Liangshan's Li Kui is with Chai at that time as he has been ordered to stay away from the stronghold, at least temporarily, as an appeasement to Zhu Tong.

When told of Yin's death, Gao Lian is furious and orders Chai be arrested, dismissing the latter's danshu tiequan as a piece of empty and obsolete document.

After Gongsun Sheng defeats Gao Lian in a battle of magic, the outlaws flock into the prison to search for Chai Jin.

Chai Jin is placed in charge of Liangshan's accounts with Li Ying after the 108 Stars of Destiny came together in what is called the "Grand Assembly".

He participates in the campaigns against the Liao invaders and rebel forces in Song territory following amnesty from Emperor Huizong for Liangshan.