Objective: To investigate the expression of adipose triglyceride lipase (ATGL) in hepatocellular carcinoma (HCC) tissues and cell lines, and to explore the role of ATGL in proliferation, migration and invasion of HCC cells. Methods: The expression of ATGL protein in 57 pairs of HCC tissues and their corresponding adjacent normal liver tissues as well as 12 kinds of HCC cell lines was detected by Western blotting. The recombinant lentiviruses (GV248-shATGL-1, -2, and -3) carrying specific shRNAs targeting ATGL gene were infected into HCC cell lines Huh7 and MHCC-97L. The negative control shRNA-carried lentivirus (GV248-shNC) was used as the negative control. The efficiency of ATGL gene-silencing was verified by real-time fuorescent quantitative PCR and Western blotting. Furthermore, the effects of ATGL gene-silencing on proliferation, migratory and invasive abilities of HCC cells were detected by CCK-8 assay and Transwell chamber assay, respectively. Results: Compared with the corresponding adjacent normal liver tissues, the expression of ATGL protein was significantly up-regulated in 49% (28/57) and down-regulated in 28% (16/57) of HCC tissues. There was no significant difference in ATGL expression between HCC tissues and the corresponding adjacent normal liver tissues in 23% (13/57) of HCC cases. The proliferation of Huh7 and MHCC-97L cells was suppressed after ATGL gene-silencing (both P<0.05). And the migration and invasion abilities of Huh7 and MHCC-97L cells with ATGL gene-silencing were significantly decreased as compared with those in the negative control group (all P<0.01). Conclusion: The expression of ATGL is commonly up-regulated in HCC tissues. ATGL genesilencing can suppress the proliferation, migration and invasion of HCC cells.