Objective: To investigate the action of the chemotactic factor fractalkine and its receptor CX3CR1 in the pathogenesis of hepatopulmonary syndrome (HPS) in rats. Methods: Forty rats undergoing common bile duct ligation were equally randomized into model group and therapeutic group, and 5 rats subjected to isolation of the common bile duct only were served as sham operation group. Rats in therapeutic group received intraperitoneal injection with CX3CR1-neutralizing polyclonal antibody on postoperative day (POD) 15 to 28, while rats in model group and sham operation group were given normal saline of the same volume instead. On POD 29, rats were sacrificed, their liver function and arterial blood gas were determined, and the pathological changes, accumulation of pulmonary intravascular macrophages (PIM), microvessel density (MVD) and CX3CR1 expression in the lung tissues of rats were examined. Results: Compared with sham operation group, rats in model group showed significantly increased serum levels of alanine transaminase (ALT), alkaline phosphatase (ALP) and total bilirubin (TRIL), decreased arterial partial pressure of oxygen (PaO2), increased alveolar-arterial oxygen gradient (A-aDO2), clear pathological changes, and increased levels of PIM (CD86 expression), MVD (CD34 expression) and CX3CR1 expression in the lung tissues (all P<0.05); rats in therapeutic group showed liver function impairments as well, which however were milder than those in model group (all P<0.05), while there were no significant pathological changes in the lung tissues, and no obvious changes in arterial blood gas indexes and lung PIM, MVD and CX3CR1 expression (all P>0.05). Conclusion: Increased fractalkine/CX3CR1 expression and binding is an important signaling pathway for pulmonary macrophage aggregation and microvascular proliferation in HPS, and blockage of this pathway may inhibit the occurrence and development of HPS.