  Using electron-spin-resonance (ESR) technique we investigate the magnetic
structure of CuCrO2, quasi-two-dimensional antiferromagnet with weakly
distorted triangular lattice. Resonance frequencies and the excitation
conditions in CuCrO2 at low temperatures are well described in the frame of
cycloidal spin structure, defined by two susceptibilities parallel and
perpendicular to the spin plane and by a biaxial crystal-field anisotropy. In
agreement with the calculations, the character of the eigenmodes changes
drastically at the spin-flop transition. The splitting of the observed modes
can be well attributed to the resonances from different domains. The domain
structure in CuCrO2 can be controlled by annealing of the sample in magnetic
field.
