Novel bulk ZnO porous nanosolids were pre- pared by a unique solvothermal hot-press method, using ZnO nanoparticles and several kinds of solvents as the start- ing materials. It was found from the experiments that ZnO nanoparticles underwent a “self-assembly process” under some specific hydrothermal hot-press conditions. As a result, some “nanoflowers” formed. The results showed that porous nanosolids with uniform pore diameters could be obtained when water distributed uniformly among the ZnO nanopar- ticles. On the contrary, if the uniformity of the distribution of water was poor, “nanoflowers” would appear in the wa- ter-rich region. It was also found that the photoluminescence of ZnO porous nanosolids was affected by the self-assembly phenomenon. In addition, the results also showed that, both the volume and diameters of the pores could be adjusted by changing either the hot-press temperature, pressure or the kinds of solvents. Novel bulk ZnO porous nanosolids were pre- pared by a unique solvothermal hot-press method, using ZnO nanoparticles and several kinds of solvents as the start-ing materials. It was found from the experiments that ZnO nanoparticles underwent a “self-assembly process” under some specific hydrothermal hot-press conditions. As a result, some “nanoflowers” formed. The results showed that porous nanosolids with uniform pore diameters could be obtained when the water was distributed among the ZnO nanoparticles. of the distribution of water was poor, “nanoflowers” would appear in the wa-ter-rich region. It was also found that the photoluminescence of ZnO porous nanosolids was affected by the self-assembly phenomenon. , both the volume and diameters of the pores could be adjusted by changing either the hot-press temperature, pressure or the kinds of solvents.