Background and Aims Many studies have demonstrated that the regulation mode of endogenous competition between the long noncoding RNAs (lncRNAs) and the microRNAs (miRNAs), as well as their target genes, is closely related to the occurrence and development of malignant tumors. The authors' team has previously found a binding site between lncRNA GAS8-AS1 and miR-135b through software prediction. However, it is unclear whether there is competition between them in hepatocellular carcinoma (HCC) and their actions. Therefore, this study aims to investigate the expressions of lncRNA GAS8-AS1 and miR-135b in HCC tissue and their clinical significance.Methods The specimens of cancer and adjacent tissues from 110 patients with HCC undergoing surgical resection in Qinghai University Affiliated Hospital from February 2017 to February 2019 were collected. qRT-PCR was used to detect the expressions of lncRNA GAS8-AS1 and miR-135b, and their associations with clinicopathologic features and the prognosis of patients were analyzed.Results The expression of lncRNA GAS8-AS1 in HCC tissue was significantly lower, while the expression of miR-135b was significantly higher in HCC tissue than in paracancerous tissue (both P<0.05). Their expression levels were all related to the Edmondson stage, TNM stage, degree of differentiation and lymph node metastasis in HCC patients (all P<0.05). The 3-year overall survival rate of patients with low expression of lncRNA GAS8-AS1 or high expression of miR-135b was significantly lower than that of patients with high expression of lncRNA GAS8-AS1 or low expression of miR-135b, respectively (both P<0.05). Low expression of lncRNA GAS8-AS1 and high expression of miR-135b together with high Edmondson grade, advanced TNM stage, and history of hepatitis B were independent risk factors for the prognosis of HCC patients (all P<0.05).Conclusion There is low expression of lncRNA GAS8-AS1 and high expression of miR-135b in HCC tissue, and the competitive state of their expressions may be closely associated with the initiation and progression of HCC as well as the prognosis of patients.