AbstractNutation spectroscopy of63Cu nuclei at zero static magnetic field is explored as a method for the determination of the quadrupole asymmetry parameters η of Cu sites in copper oxides, with special emphasis on high‐Tcsuperconductors. Since the nutation spectra reveal the actual radio frequency (rf) intensities experienced by the63Cu nuclei, the method also provides a verification of a quantitative Cu spin counting procedure based on integration of nuclear quadrupole resonance (NQR) echo‐signal intensities over wide frequency ranges. The paper presents numerical simulations of spectra and signal intensities that were obtained with a density‐matrix formalism whereby the spin dynamics is described as precessions in a 3D operator space. The quantitative effects of the echo refocusing pulse, rf amplitude fluctuations, and variations in η are examined. Examples of63Cu NQR nutation spectra are shown for randomly oriented powders of Cu2O and YB