The aim of this research was to study the clinical significance and expression of CD4+CD25+ regulatory T cells (Tregs) and p3Forkhead transcription factor-3 (Foxp3) in peripheral blood of patients with gastric carcinoma (GC) and to investigate the effects in the occurrence and development process of GC, to further comprehend their clinical values and provide a theoretical basis for the early diagnosis and immunotherapy of GC. The expression levels of CD4+CD25+Foxp3+Tregs in GC patients, at TNM staging, differentiated degree, lymphatic metastasis, cancer sites and cancer diameter of GC, were analyzed within the groups. The comparison of the expression levels of CD4+CD25+Foxp3+Tregs in peripheral blood between the GC group and the healthy control group showed a statistically significant difference. At TNM staging within the groups, pairwise comparisons of the expression levels of CD4+CD25+Foxp3+Tregs indicated that differences among the stage I+II group, stage III group and stage IV group were statistically significant. The expression levels of CD4+CD25+Foxp3+Tregs are closely relative to the occurrence and development of GC, providing theoretical bases and evidence for the early diagnosis, prognosis evaluation and immunotherapy of GC.