In addition to the traditional treatment mode of colorectal cancer (Colorectal cancer,CRC), anti tumor immune treatment gradually becomes the focus .In addition to some clinical pathological factors which affect the prognosis of colorectal carcinoma ,the host′s immune response becomes a hotspot .Treg cells involves in immune reaction through immunomodulatory mechanism .Foxp3 as a regulator of Treg plays an important role though suppress proliferation and differentiation of immune cell .The relationship between the expression of Foxp 3 in Treg and prognosis in patients with colorectal cancer is closely .The review is to clarify the basic characters of Foxp3 and Treg,the mechanism of Foxp3+Treg cell,the significance between the expression of Foxp 3 in Treg and the prognosis of colorectal cancer .