The whole procedures of this clinical trial were blinded to both patients and investigators.Patients in both groups received the same ordinary treatment. Meanwhile, MSCs and MNCs were transplanted into the impaired lower limbs respectively. Follow-up index include: efficacy (pain,ulcer healing rate, lower limb amputation rate and ,ankle-brachial index,Transcutaneous oxygen pressure,magnetic resonance angiography) and safety (infection of the injection site, immunological rejection, and tumour generation).