FIELD : medicine.SUBSTANCE : invention relates to radiobiology and experimental medicine and can be used to simulate radiation cystitis. To do this, carry out anesthesia of the animal, the formation of the irradiation area of the lead window, followed by irradiation of the bladder on a linear accelerator. At the same time, the irradiation field is centered on the animal on the table of the linear accelerator over the light field and anatomical bone landmarks. 2.5 cm field is formed in the direction of right-left and 2.3–4.0 cm in the direction of the animal' s head-tail in the projection of the lower third of the bladder. Tissue-equivalent bolus with a thickness of 1?cm is set on top in the field of irradiation. Source-surface distance is set to 100 cm. Irradiation is performed by photons with a limit energy of 6 MeV quanta. When creating a model on a rat, irradiation is carried out with one fraction at a dose of 25 Gy. When creating a model on a rabbit, irradiation is carried out with 5 fractions with a single focal dose of 6 Gy to a total focal dose of 30 Gy.EFFECT : method ensures the creation of a model of radio-induced cystitis without the application of additional suffering to experimental animals in order to conduct scientific research allowing with a high degree of reliability to carry out preclinical studies of drugs for treatment of radiation cystitis.1 cl, 8 dwg, 2 ex