Aim: To explore the effect of autologous bone marrow stem cell (BMSC) implantation in treating severe lower limb ischemia, and compare the effects of two different implantations. Methods: From March 2003 to April 2004, 35 limbs with severe ischemia of 32 patients were divided into 2 groups. Group 1 (18 limbs of 16 patients) received autologous BMSC implantation by local muscular injection into the suffering limbs; Group 2(17 limbs of 16 patients) received autologous BMSC implantation by intraarterial injection into the suffering limbs. Results: The total relieved rate of pain was 76.5% (13/17) and 93.3% (14/15) in the two groups respectively, and the total improvement rate of cold sensation was 100% (16/16, 14/14) . Limb salvage rate was 83.3% (15/18, excluding one patient with necrotic foot before foot amputation) and 94.1% (16/17) in the two groups respectively. Increases of ankle/brachial index (ABI) were found in 8 of 18 limbs (44.4%) in group 1 and 7 of 17 limbs (41.2%) in group 2. After arterial angiography was performed in 15 limbs of 14 patients, angiogenesis of collateral vessels was found at different degrees. There were 20 suffering limbs with increase of transcutaneous oxygen pressure (tcPO2) to more than 2.67 kPa (the lowest critical value for amputation used in clinic at present). Conclusion: Autologous BMSC implantation is a simple, safe and effective method for severe lower limb ischemia. Though the results of long-term follow-up are not supported enough, it is still a selectable method undoubtedly for the patients who cannot receive lower limb bridging due to lack of arterial outflow tract, or for the senile patients, who are physically weak or with other diseases, cannot receive bridging.