Inorganic adsorbents based on manganese oxides are widely used for the purification of aqueous media from heavy metal ions, radionuclides and organic pollutants. That is due to the features and multiplicity of the crystalline structure, which consist of MnO6 octahedra, forming layered (birnessite) and channel (cryptomelane, todorokite) structures with a given hollow size in the range of 4-9 Å. Manganese oxides with a spinel structure as adsorbents attract particular attention. Among them Li-Mn spinels with LiMn2O4, Lil.6Mnl.6O4 and Li1.33Mn1.67O4 composition are one of the most promising materials for the selective Li+ ions adsorption from natural brines and process waters, which formed during recycling of Li-ion batteries and super capacitors. Ion exchange materials based on Li-Mn spinels are characterized by high adsorption capacity and selectivity to Li+ ions. However, the low crystal structure stability in adsorption-desorption processes, due to partial dissolution in an acidic medium and the Mn2+ ions leaching into solution, are key disadvantages limiting widespread application. The work aimed to study the regularities of Li1.33Mn1.67O4 spinel synthesis and to determine the main factors affect on the phase composition, structure, and adsorption properties of Li-Mn adsorbents. Li1.33Mn1.67O4 spinels were obtained by hydrothermal, sol-gel, and solid-phase synthesis methods. To form the spinel structure, all obtained samples were calcined at 500 °C for 5 h. The crystal structure was studied on an Advance D8 X-ray diffractometer (Bruker, USA). The FT-IR spectra of the prepared materials were recorded on an IR spectrometer with a Fourier transducer Tenzor-27 (Bruker, USA). The textural characteristics of the adsorbents were studied by nitrogen adsorption-desorption method on a porosity and surface analyzer ASAP 2020 (Micromeretics, USA). Surface morphology and chemical composition were studied using a JSM-5610 LV scanning electron microscope with a JED-2201 (JEOL, Japan). The adsorption experiment was performed under batch test with lithium nitrate model solutions. In this work, the physicochemical and adsorption properties of the obtained Li-Mn spinels were studied. The main factors determine Li1.33Mn1.67O4 spinel adsorption-selective properties were established. It was shown that preparation of Li-Mn spinels modified by doping with transition metal ions (Co2+, Ni2+, Cr3+, Mg2+, Al3+, Fe3+) can lead to increase the stability of adsorbents crystal structure during multiple adsorption-desorption cycles. Acknowledgements: This work was supported by the State Committee on Science and Technology of the Republic of Belarus and the Belarusian Republican Foundation for Fundamental Research within the framework of a joint international Belarusian-Uzbekistan project.