30 patients are divided into 2 groups, one treatment group and one control group.Treatment group will be implanted with peripheral blood stem cell and receive convention stroke therapy ,and control group only receive convention stroke therapy. We expect that transplantation of the peripheral blood CD34+ cells has the potential of significant benefit to neurological recovery. In a previous phase I clinical trial, we have shown that transplantation of CD34+ cells obtained from the peripheral blood of the chronic stroke patients was safe and beneficial for neurological recovery. We expect this trial can further prove the efficacy of this treatment method.