Chronic critical limb ischemia is defined as ischemia which generally endangers the distal part of a limb. If the ischemia is unrelenting, there is a high risk that amputation will be required. These critical limbs were amputated as an initial treatment long ago. Now it becomes clear that disabling patients have very poor quality of life after major amputation, and ischemic leg produces noxious substances which circulates whole body. So that primary amputation should not be a first choice for the most of the cases. And excellent techniques or new surgical materials bring successful vascular reconstruction to critical limb ischemia. Since we have not a clear definition, European and US criterion seems to be useful for a while. Macrocirculation is represented by ankle systolic pressure and microcirculation by transcutaneous oxygen pressure as well. Its value of les than 10 mmHg means urgent critical condition. Main surgical repairs include below knee bypass using autovein or fine profundaplasty with or without PTA. Usually patients should receive general cares because of high risks.