ZnO nano-bulk materials with high density and low brittleness is prepared on CS-1B 6×8000kN cubic high pressure apparatus. Grain sizes and microstructures of the samples have been characterized by X-ray diffraction and field emission scanning electron microscopy. The Raman spectra of polar semiconductor ZnO are studied by Raman spectrophotometer in the range of 50—500cm-1. No obvious size confinement effect is found in the polar semiconductor oxide.