Duan Mopei was a Duan Xianbei chief and the cousin of chief Duan Jilujuan. In 313, Shi Le's general Kong Chang made a surprise attack against Duan Jilujuan's forces during the siege of Xiangguo, capturing Mopei. Most of Shi Le's generals wanted to execute Mopei, but Shi treated him with civility and had him released to his cousin, who withdrew from the siege and forsook his alliance with Eastern Jin.