How does guanxi facilitate corrupt transactions? Utilizing fieldwork data and published materials, this paper investigates how guanxi practices distort the formal military promotion system and facilitate the buying and selling of military positions in the People's Liberation Army (PLA). It identifies the three key functions of guanxi in facilitating corrupt transactions: communication, exchange and neutralization. Guanxi enables effective and safe communication among corrupt military officers, holds transaction partners to their word, and neutralizes their guilt about committing corrupt acts.