Abstract: Oligomeric hydroxyaryloxycyclotriphosphazenes P3N3Cln(OC6H5)x(OC6H4OH)y are obtained by the polycondensation of phenoxychlorocyclotriphosphazenes with the general formula P3N3Cl(6 −x)(OC6H5)x (x = 3.1, 4.5) with an excess of resorcinol under homogeneous (pyridine) and heterogeneous (K2CO3) acceptance of HCl in a yield of 60–85%. Full substitution of the chlorine atoms in the specified oligomers (n = 0) under homogenous acceptance of HCl by pyridine is reached only at a molar ratio of phenoxychlorocyclophosphazene : resorcinol = 1 : 12; the formed oligomers contain up to 3% Cl at a ratio of 1 : 6. The structure of the compounds present in the composition of oligohydroxyaryloxycyclotriphosphazenes and their relative concentration are determined by 31P NMR spectroscopy and MALDI-TOF mass spectrometry. © 2020, Pleiades Publishing, Ltd.