Abstract: Memory T cells (Tm), a component of the human immune system, play a crucial role in immune response. Central memory T cells (Tcms) are produced by naïve T cells after antigen activation and exhibit long-term memory, facilitating homing to lymph nodes for antigen re-stimulation. The efficacy of tumor immunotherapy and the occurrence and treatment of adverse events are closely related to T cell function. Tcms not only serve as a defense line in mediating immune responses but also hold promise as predictive biomarkers of efficacy. Currently, the impact of intestinal flora on tumor immunotherapy has attracted considerable attention. The flora itself and its metabolites modulate the efficacy of immune response by influencing the tumor microenvironment (TME), requiring in-depth investigation into the immune cell mechanisms. This review summarizes research progress on the functions of Tcm on tissue differentiation, surface markers, roles of Tcms in tumor immunotherapy, and the association between the intestinal flora and Tcms.