Abstract: To investigate the impact of HBx on EP expression in HL-7702 cells and its correlation with invasion and metastasis. Methods: Based on established HL-7702 cells with HBx expression ( HL-7702/HBx ), HBx RNAi vector was used to construct the HL-7702 cell line with inhibited HBx expression ( HL-7702/HBx-siRNA ) and measured the change of the PGE2 concentration in the supernatant expression of EPs and MMPs mRNA in this cell line, as well as the control cell lines. The change of MMPs activities of invasion and metastasis upon inhibition of EP2 expression using the methods of transient transfection of EP2-siRNA, Western-blot, Gelatin zymography, and Transwell chamber technology were also detected. Results: (1) PGE2 concentration, EP2, and MMP2 relative expression in HL-7702/HBx cells significant increased ( P < 0.05 ) compared with the control cells. The values were 123.9 ± 9.9 pg/mL, 0.445 ± 0.025 pg/mL, and 0.226 ± 0.016 pg/mL, respectively. Consequently, the values decreased after the HBx expression was inhibited ( P < 0.05 ), and the resulting values were 78.0 ± 5.9 pg/ml, 0.336 ± 0.007 pg/mL, and 0.117 ± 0.012 pg/mL. (2) After EP2 expression was inhibited, the MMP2 and MMP9 activity, the ability of cell invasion, and migration were not changed in HL-7702 cells, however, the MMP2 activity, and the cell invasion ability decreased significantly in HL-7702/HBx cells ( P < 0.05 ). The amount of invasion cell was from 64.4 ± 3.4/field to 55.2 ± 2.2/field. Conclusion: HBx could promote the EP2 expression and MMP2 activity and may increase the invasion ability of HL-7702 cells by upregulating the EP2 expression. The inhibition of EP2 is of potential value for the treatment research on invasion and metastasis of liver cancer with HBV infection.