Objective:This study investigates the expression of long non-coding RNA termed amine oxidase, copper containing 4, pseudo-gene (AOC4P) in hepatocellular carcinoma (HCC) and its relationship with clinicopathological factors and patient prognosis. Methods:The expression of AOC4P in 106 HCC tissues and adjacent non-tumor tissues were detected using qRT-PCR. The relationship between AOC4P expression and clinicopathological factors, as well as patient prognosis, in HCC was analyzed. Results:The relative expression of AOC4P in the cancer tissues was 0.66±0.34, which was significantly lower than the relative expression in adjacent non-tumor tissues, i. e., 1.45±0.63 (P<0.05). Univariate analysis showed that low AOC4P expression was correlated with tumor size, lymph node metastasis, and TNM stage (P<0.05). The group with high AOC4P expression levels has longer survival time compared with the group with low AOC4P expression levels. Cox multivariate regression analysis showed that AOC4P expression, lymph node metastasis, and vascular in-vasion were all independent factors that affect prognosis of patients. Conclusion:AOC4P expression was reduced in HCC tissues, and AOC4P may play crucial roles in the occurrence and development of HCC. For patients with poor prognosis, low AOC4P expression is an independent risk factor for patients with HCC. Thus, AOC4P expression may be used as a molecular marker for HCC.