The results of the investigations are presented on the effect of irradiation with electrons, ions of inert gases (Ne, Ar, Kr) and oxygen on the structure and properties of Nd-doped barium cerate by the methods of X-ray diffraction analysis, scanning electron and atomic force microscopy, thermal desorption spectroscopy. It is shown that the low-energy irradiation with Ne and Ar ions stimulates the blistering processes on the surface, whereas the high energy ion irradiation by Ne, Ar, Kr ions the cerate surface undergoes the following stages of the spherulite growth - nucleation, growth (view of cauliflower), formation of spherulitic crust, correspondingly. The similar structures were not observed in the case of irradiation with high-energy oxygen ions. It is noticed that the irradiation of cerates with electrons leads to the formation of nano-sized acicular structures on the surface. The radiation of lowenergy ions of inert gases led to the conversion of most of the neodymium into a tetravalent state, as has been shown, accompanied by an increase in oxygen release and a decrease in water compared to non-irradiated cerate, as well as the independence of the amount of gases from the type of ions. Based on the data on thermal desorption of water and oxygen molecules from the irradiated barium cerate it was assumed that the irradiation stimulates the oxidation to Nd4+.