To investigate the effect and side effect of prepared Rehmannia polysaccharide (PRP) associated with stanozolol in treating chronic aplastic anemia (CAA). Thirty-four cases of CAA were treated by PRP liquid associated with stanozolol, course of 3 week treatment, and control group (17 cases of CAA) was treated by stanozolol alone. Effective rate was 85.3% in treatment group, and that of control group was 58.8%, there was significant difference between them (P < 0.05). Symptom remission of treatment group was earlier than that of control group, symptom scoring between two groups, the difference was highly significant (P < 0.01). Blood cell had a distinct elevation after treatment with PRP associated with stanozolol, and had a significant difference in comparing with pre-treatment in treatment group (P < 0.01). Side effect of PRP was not found during treatment of CAA. PRP associated with stanozolol to treat CAA has an additional effect, it can accelerate symptom remission without any additional side effect.