Background: Long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) plays an important role in the pathogenesis and development of several types of cancer. However, the functional mechanism of NEAT1 in hepatocellular carcinoma (HCC) remains unclear. Methods: The NEAT1 and miR-129-5p expression in HCC tissues and cell lines were quantified by means of qPCR. The effects of NEAT1 expression inhibition or up-regulation in HCC cell lines were analyzed in terms of cell viability and apoptosis. Biological software was used to predict the binding sites of NEAT1 and miR-129-5p. The expression of the miR-129-5p target molecules VCP and IB was detected by using Western blotting. The effect of NEAT1 on tumor growth was observed in mouse models of transplanted hepatoma. Results: In the present study, it was concluded that the expression of NEAT1 was significantly increased in the HCC tissues and cell lines. Meanwhile, after down-regulating NEAT1 expression in HepG2/Huh7, the cell viability was significantly lowered, while the corresponding rate of apoptosis was significantly increased. Additionally, it was found that the NEAT1 and miR-129-5p expression showed a negative correlation in HCC tissues. It was further proved that there was a certain negative regulatory mechanism between NEAT1 and miR-129-5p, which was related to the expression of VCP and IB. The mouse model experiments confirmed that the interference with NEAT1 expression inhibited tumor growth. Conclusions: The study concluded that the overexpression of NEAT1 inhibited the expression of miR-129-5p by regulating VCP/IB, thereby promoting the proliferation of HCC cells.