The stem bark of Eucommia ulmoides Oliv. is commonly used for the treatment of hypertension, rheumatoid arthritis, lumbago, and ischialgia in traditional Chinese medicine. This study was to determine whether the crude polysaccharides (EUPs) isolated from the stem bark of E. ulmoides had beneficial effects on lupus-like syndrome in mice. BALB/c mice were immunized with CJ-S(131) in Freund's complete adjuvant on day 0, and then boosted on day 14. EUPs 15 or 30 mg kg(-1)·day(-1), or prednisone 5 mg kg(-1)·day(-1) was given to BALB/c mice intragastrically from day 0 to 34. Treatment with EUPs 15 or 30 mg kg(-1)·day(-1) for 35 days protected kidney from glomerular injury with reduced immunoglobulin deposition and lowered proteinuria. The increased production of serum autoantibodies and total immunoglobulin G (IgG) was also inhibited. These findings suggested that Eucommia polysaccharides had a beneficial effect on systemic lupus erythematosus-like syndrome induced by CJ-S(131) in BALB/c mice.