The present invention refers to a method for blood purification by means of hemodialysis and/or hemofiltration, wherein to the blood in the extra-corporeal circuit (10) of the hemodialysis and/or hemofiltration device (20) a substitution solution is added upstream as well as downstream of the hemodialyser and/or hemofilter (20). A purification effect remaining constant with a high purification performance is achieved in that one or several of the operational and/or blood parameters are controlled and that the control is carried out using at least one of the infusion rates of the substitution solutions supplied upstream or downstream of the hemodialyser and/or hemofilter. The present invention also refers to a hemodialysis and/or hemofiltration apparatus for the performance of the inventive method. <；IMAGE>；
