Objective To understand the effect of blood flows on dialysis adequacy by measuring blood flow of access,Kt/V and urea reduction ratio (URR) of maintenance hemodialysis patients. Methods The blood flow of access, Kt/V and URR at the beginning of one hemodialysis session were observed and calculated. The relationship between the blood flow of access and Kt/V and URR were analyzed. Results We found that there was a significant positive correlation between the blood flow of access and Kt/V and URR (r1=0.448, P<0.001; r2=0.413, P<0.001 respectively). As the blood flow reduced from 300 ml/min to 200 ml/min, Kt/V and URR reduced from 1.33±0.33、(68.19±8.86)% to 0.99±0.31、(58.59±13.19)% respectively, reduced 25.56%、14.08%. Conclusion The blood flow of access of the chronic maintenance hemodialysis patients is a valuable index of the hemodialysis quality. 