Zhao Xin (Chinese: 赵信; Wade–Giles: Chao Hsin), was originally a marquis of Xiongnu stock, who previously surrendered to the Han Dynasty. His name Zhao Xin was probably adopted through during his service at Han. He was one of the six generals led by Wei Qing during an expedition in 123 BC, and led a 3,000-strong vanguard forces along with fellow general Su Jian. Upon clashing with the Xiongnu forces, he defected back to Xiongnu, while Sun Jian managed to escape after his forces were annihilated. A Xiongnu fortress named after him was constructed near the Khangai Mountains, soon after his submission to Yixixie Chanyu. That fortress was later completely destroyed by Wei Qing's forces during the finishing phase of the Battle of Mobei.