【Abstract】 Objective To understand the epidemiology of hemodialysis patients by analyzing the registration data of hemodialysis patients from 109 blood purification units in Beijing in 2007. Methods Based on patients’ age, gender and primary disease, we stratified the dialysis age of the 5065 patients with detailed information collected from the 109 dialysis units. Results The number of maintenance hemodialysis patients reduced gradually with the increasing of dialysis age. The number of patients with dialysis age 1～2 years decreased to 46.0% of the ones with dialysis age 0～1 year. Thereafter, the patient number in a dialysis age group was about 75% of the number in a dialysis age less one year group. The male-to-female ratio in patients withdrawing from dialysis was similar to the ratio in the patients as a whole. However, female patients seem to endure dialysis better than male patients. In every dialysis age group, the patients at 50-80 years old were the largest subgroup. The ratios of those younger than 30 years old and older than 80 years old were remarkably high (59.5% and 41.0%, respectively) in the patient group of dialysis age 0-1 year, but the ratios decreased greater than other age subgroups in the dialysis age 1-2 years group. The major primary diseases leading to hemodialysis were primary and secondary glomerular diseases, with which patients usually had longer dialysis age. Conclusion The number of maintenance hemodialysis patients decreased with the increase of dialysis age. The highest rate of patients withdrawing from dialysis was found around the first year of dialysis, and then decreased and changed within a limited range. The average dialysis age was longer in women than in men. In every dialysis age group, the number of patients at 30-80 years of age was greater than that of other age subgroups. Primary diseases leading to hemodialysis correlated to the dialysis age.