Objectives The work discussed the expression level circular RNA (circRNA) hsa_circ_0079598 for gastric cancer (GC) patients as well as clinicopathological significance. Methods qRT-PCR was utilized for determining the expression level of hsa_circ_0079598 in GC cell lines, 40 GC tissue pairs and their paracancerous tissue specimens, 60 pairs of preoperative and postoperative plasma specimens of GC patients, 20 plasma specimens of patients with gastric polyps, and 60 plasma specimens of the healthy control group. Besides, the correlation with clinicopathological parameters was analyzed. Tumor indices glycan antigen 199 (CA199), glycan antigen 724 (CA724), and pepsinogen I (PGI) were combined to evaluate their auxiliary diagnostic value. The values of hsa_circ_0079598 in the prognosis of GC patients were analyzed using survival curves. Results The relative expression of hsa_circ_0079598 in the cancerous tissues of GC patients was lower than that of their paracancerous tissues (p=0.004). The relative expression of plasma hsa_circ_0079598 in GC patients was lower than that of the healthy control group (p Conclusions Hsa_circ_0079598 was low-expression in cell lines, plasma, and GC tissues, which was related to the progress and prognosis of GC. Hsa_circ_0079598 combined with CA199, CA724, and PGI detection can improve the diagnosis of GC.