The Xubu (Chinese: 須卜; pinyin: Xūbǔ; Wade–Giles: Hsü-pu; LHC: *sio-pok) was a tribe of the Xiongnu that flourished between 3rd century BCE and the 4th century CE. Chinese annals noted that the Xubu tribe replaced the Huyan tribe, which was an earlier maternal dynastic tribe of the dynastic union with the paternal dynastic tribe Luandi. The traditional system of conjugal unions is a form of the nomadic exogamic society. The male members of the maternal dynastic line were not eligible to be chanyu, only the male members of the Luandi line, whose father was a Luanti Chanyu, and mother was a Xubu Khatun (Queen) were eligible to be chanyu. A Xubu could only become a chanyu after a palace coup.
The Huyan tribe moved from the Right (Western) Wing, where the maternal dynastic tribe is traditionally assigned, to the Left (Eastern) Wing. The Book of the Later Han (chapter 89, l. 7b) stated that of the noble tribes other than Luanti, Huyan, Xubu, Qiulin and Lan, Huyan already belonged to the dominating Left Wing, and Lan and Xubu belonged to the Right Wing. The Book of the Later Han also names the dynastic Luandi tribe with a composite name Xulianti, implying a merger of the two dynastic lines.