Effects of long intergenic non-coding RNA (lincRNA)-p21 on the proliferation, migration and invasion ability of HepG2 liver cancer cells were assessed to explore the underlying mechanism. The lincRNA-p21 small interfering RNA (siRNA) lentivirus vector was constructed, transfected and screened to obtain a stable cell line, which constituted the experimental group. At the same time, the empty virus vector was transfected as the control group. The messenger RNA (mRNA) expression of lincRNA-p21 in cells was detected via reverse transcription-polymerase chain reaction (RT-PCR). The proliferation ability of cells was detected via Cell Counting kit-8 (CCK-8) assay. Transwell chamber experiment was used to observe cell migration and invasion ability. Compared with that in the control group, the mRNA expression level of lincRNA-p21 in cells in the experimental group was obviously decreased (p<0.05). Results of CCK-8 showed that the proliferation ability of liver cancer cells was remarkably higher than that in the control group after knockout of lincRNA-p21 (p<0.05). Results of the Transwell chamber experiment revealed that the invasion and migration ability of HepG2 cells in experimental group was markedly higher than that in control group (p<0.05). When lincRNA-p21 was inhibited, the proliferation, invasion and migration ability of HepG2 cells were significantly enhanced, and the apoptosis rate was significantly decreased. Thus, lincRNA-p21 on the surface may play an inhibitory role in the occurrence, development and metastasis of liver cancer.