Scientific baase: Secondary hyperparathyroidism with expression of parathyroid hormone increased in serum is common in dialysis patients and closely related to cardiovascular disease and osteodystrophy. Purpose: To study the concentration of parathyroid hormone and correlation with calcium, phosphorus, alkaline phosphatase in patients with chronic renal failure. Subjects and Methods: 161 patients with chronic renal failure, including 106 males and 55 females, mean age (54.7 + or - 13.3), treated at No.108 hospitals from 3/2008 - 10/2009. Patients received physical examination, blood tests: urea, creatinine, phosphorus, total calcium, alkaline phosphatase, parathyroid hormone. Results: - PTH concentrations increased with the extent of renal impairment (p 0.05). PTH levels correlated with serum creatinine (r