Objective　To explore the cause, diagnosis and treatment of retroperitoneal fibrosis.Methods　5 cases of retroperitoneal fibrosis were respectively treated by moving ureter into abdomen cavity, encapsulating with pediculate omenta and ilel ureter.Results　Following-up of 5 cases for 1 to 3 years, all cases had normal renal functions and hydronephrosis were much decreased.Conclusions　Intravenous urogenous(IVU),retrograde pyelography(RGP) and computed tomography (CT) are important methods to diagnose the disease. And the treatment method chosen depends on the range, location of ureterostenosis, and whether the ureter is open or not.