An anticoagulation control device for application during extracorporeal blood treatment, said anticoagulation control device comprising: a means, in particular a blood pump , for conveying blood in a first line section ; a means, in particular a pump , for supplying a number of biologically and/or pharmacologically active substances of negative total charge, in particular heparin, to the blood in the first line section ; a means, in particular a plasma separator , for separating blood added with the number of biologically and/or pharmacologically active substances of negative total charge into corpuscular blood components and blood plasma; a means, in particular a plasma pump , for conveying the separated blood plasma in a second line section via an anion exchanger for adsorption of lipopolysaccharides; a means for bringing the treated blood plasma and the corpuscular blood components together in a third line section , and a means for determining a first volumetric flow rate of the blood plasma fraction in the first line section before the supplying of the number of biologically and/or pharmacologically active substances of negative total charge, in particular at the blood pump ; and a means for determining a second volumetric flow rate of the blood plasma in the second line section upstream or downstream of the anion exchanger , in particular at the plasma pump ; characterized by a control unit which is adapted to control a quantity of the number of biologically and/or pharmacologically active substances of negative total charge, wherein said substances are supplied to the blood before the separating, on the basis of the ratio of the first volumetric flow rate and the second volumetric flow rate, in such a way that, after the treated blood plasma and the corpuscular blood components have been brought together, a concentration of the number of biologically and/or pharmacologically active substances of negative total charge in the third line section obtains a predetermined, in particular constant, target value. a means, in particular a blood pump , for conveying blood in a first line section ; a means, in particular a pump , for supplying a number of biologically and/or pharmacologically active substances of negative total charge, in particular heparin, to the blood in the first line section ; a means, in particular a plasma separator , for separating blood added with the number of biologically and/or pharmacologically active substances of negative total charge into corpuscular blood components and blood plasma; a means, in particular a plasma pump , for conveying the separated blood plasma in a second line section via an anion exchanger for adsorption of lipopolysaccharides; a means for bringing the treated blood plasma and the corpuscular blood components together in a third line section , and a means for determining a first volumetric flow rate of the blood plasma fraction in the first line section before the supplying of the number of biologically and/or pharmacologically active substances of negative total charge, in particular at the blood pump ; and a means for determining a second volumetric flow rate of the blood plasma in the second line section upstream or downstream of the anion exchanger , in particular at the plasma pump ; characterized by a control unit which is adapted to control a quantity of the number of biologically and/or pharmacologically active substances of negative total charge, wherein said substances are supplied to the blood before the separating, on the basis of the ratio of the first volumetric flow rate and the second volumetric flow rate, in such a way that, after the treated blood plasma and the corpuscular blood components have been brought together, a concentration of the number of biologically and/or pharmacologically active substances of negative total charge in the third line section obtains a predetermined, in particular constant, target value. <EOS>