Hybrid polymer/BaZrO3 hollow nanospheres were successfully synthesized via a simple polymer assisted hydrothermal route.Polymer additives play a key role on the formation of hollow nanospheres.The samples prepared in the absence of polymers are microcubes.The basicity also plays an important role on the formation of hollow nanospheres.In low concentration medium,the products are microcubes.Hollow spheres formed when the is larger than 4 mol/L.Pure hollow spheres could be formed with the over 8 mol/L.IR and TG data indicate the hybrid feature of the products.The polymer content(mass fraction)declined from 33 to 6 by adjusting the basicity from 8 to 16 mol/L.The diameters of nanos-pheres are tunable in the range of 300-100 nm via increasing the basicity.