Objective To study the impact of pump controlled blood flow (Qb) on blood flow in arteriovenous fistula (Qa) during hemodialysis. Methods A total of 21 maintenance hemodialysis patients with arteriovenous fistula were observed. After access to the fistula by successful puncture, the HD02 ultra- sound hemodialysis monitor was connected to it. Thirty minutes after the beginning and 30 minutes before the end of a hemodialysis session, the Qb was sequentially adjusted to 200, 250 and 300ml/min in 4 minutes apart. When blood flow was stable for 2 minutes after every change of Qb, Qa was measured by HD02 hemodialysis monitor. Patients’ heart rate and blood pressure were recorded. Results Under the Qb of 200, 250 and 300ml/min, the Qa at 30 minutes after the beginning of the hemodialysis session were 1123.0 ± 457.9, 1093.9 ± 449.8 and 1153.9 ± 436.3ml/min (P 0.05), respectively, and the Qa at 30 minutes be- fore end of the hemodialysis session were 1083.9 ± 420.9, 1042.3 ± 413.8 and 1039.2 ± 392.7ml/min (P 0.05), respectively. Patients’ heart rate and blood pressure remained unchanged. Conclusion At the beginning and the end of hemodialysis sessions, Qb in the range of 200~300ml/min did not affect the Qa significantly. Patients’ heart rate and blood pressure were stable. These results also demonstrate the stable cardiac function during hemodialysis sessions.