Objective: Transarterial chemoembolization (TACE) stands for an ideal therapy for patients with intermediate stage HCC. This study was carried out to observe the effect of gelatin sponge microparticles-transarterial chemoembolization (GSMs-TACE) on the immune function of patients with liver cancer by detecting the proportion of Treg cells in the peripheral blood of HCC patients before and after the treatment of GSMs-TACE, and to determine whether GSMs-TACE has a positive regulatory effect on the immune function of patients with liver cancer. Methods: 28 HCC patients treated with GSMs-TACE were enrolled. Flow cytometry was used to determine the Treg cell proportion in peripheral blood in all patients with HCC 1 day before GSMs-TACE, 10 days and 30 days after GSMs-TACE, respectively. Results: The Tregs cell proportion in peripheral blood of primary HCC patients was significantly higher than that of the healthy controls and was associated with various clinical indicators of HCC. The Treg cell proportion in the peripheral blood of patients with BCLC stage C liver cancer was higher than that of stage B patients; The Treg cell proportion at 10 days postoperatively was 8.85 ± 1.23%, which was significantly lower than that before the GSMs-TACE. The Treg cell proportion at 30 days postoperatively was 10.27 ± 1.28%, which remained in the low range. Conclusion: These results indicated that GSMs-TACE could exert a positive regulatory effect on the anticancer immune function of HCC patients, which may be used in combination with immune adjuvant therapies to enhance the treatment efficacy of HCC.