This work is devoted to the study of the interaction of Yersinia pseudotuberculosis OmpF porin with norfloxacin hydrochoride (Nf•HCL), a derivative of a fluoroquinolone antibiotic. Using the bilayer lipid membrane (BLM) method, it was found that water-soluble Nf•HCL molecules dissociate into ions and, binding for a short time to sites inside the channel, block the ion current through the OmpF porin pore. The study of the kinetic characteristics of this process, together with the use of the molecular docking method, made it possible to construct a model that explains the pattern of this interaction. It is proposed that inside the porin channel, on opposite sides of the constriction zone, there are two binding sites with the Nf•H+ ion, stabilized mainly by electrostatic interactions. At the same time, binding to the site located inside the channel near the vestibule formed by the outer loops of the porin leads to blocking of the current, due to the creation of spatial difficulties for the movement of K+ and Cl- ions, while binding to the site located at the exit from the channel does not prevent the passage of current.