〔Abstract〕 Objective To investigate the expression and prognosis of(progestin and adipoQ receptor family member 4,PAQR4) in hepatocellular carcinoma(HCC) and its effect on the proliferation, invasion, migration and apoptosis of HepG2 cells. Methods The HCC data in the cancer genome atlas(TCGA) database was used to analyze the expression of PAQR4 mRNA in the tissues of HCC and its prognostic significance. HepG2 cell lines of pcDNA3.1-PAQR4 experimental group and pcDNA3.1-vector control group were established. CCK-8 assay was used to detect the effect of overexpression PAQR4 on the proliferation of HepG2 cells. The scratch assay and Transwell assay were used to detect the effects of PAQR4 overexpression on the migration and invasion of HepG2 cells.PI and Annexin V double staining experiment was used to observe the effect of PAQR4 overexpression on HepG2 cell apoptosis.Results TCGA database data analysis results showed that the expression of PAQR4 mRNA in HCC tissues was higher than that in adjacent tissues(P<0. 05), and the overall survival rate of HCC patients with PAQR4 mRNA high expression group was lower than that of low expression group(P= 0. 012). Univariate regression analysis showed that PAQR4 mRNA expression level(HR:1. 104, 95%CI: 1. 051-1. 160,P<0. 001), T stage(HR:1. 816, 95%CI:1. 442-2. 287,P<0. 001), M stage(HR:3. 924, 95%CI:1. 230-12. 519,P=0. 021), pathological staging(HR:1. 879, 95%CI: 1. 466-2. 408,P<0. 001) had a significant impact on the prognosis of HCC patients. Multivariate regression analysis showed that PAQR4 mRNA expression level(HR:1. 396, 95%CI: 1. 081-1. 804,P= 0. 011) was an independent risk factor of the prognosis of HCC patients. The results of CCK-8 assay, scratch assay and Transwell assay showed that the proliferation, migration, invasion and invasion ability of HepG2 cells in the experimental group were significantly improved compared with the control group(P<0. 05). Overexpression PAQR4 could inhibit HepG2 cell apoptosis(P<0. 05).Conclusion PAQR4 is significantly up-regulated in HCC tissue and is related to the prognosis of the patients. Overexpression PAQR4 promotes the proliferation, invasion and migration of HepG2 cells, and inhibits HepG2 cells apoptosis. PAQR4 maybe a new marker for the diagnosis and prognosis of HCC.