By using Wigner distribution function, the beam combination characteristics of general astigmatic Gaussian beams are studied. The analytical formulas of intensity profiles and beam propagation factor (M2) for incoherent and coherent combinations are derived. The analytical and numerical results show that the beam quality of the resulting beam depends on the number, normalized separation distance and geometrical arrangement of beamlets. The beam quality of the coherent combination is better than that of the incoherent combination when the beam propagation factor (M2) is chosen as the criterion, whereas the beam quality of the coherent combination is not always better than that of the incoherent combination, if the power in the bucket (PIB) is adopted as the criterion.