Abstract: From barotropic quasi-geostrophic vorticity equation, the exchanges of energy and enstrophy for quasi-resonant triad waves are analysed under conditions of k₁+k₂+k₃ = Δk,l₁ + l₂ + l₃= 0 and ω₁ + ω₂ + ω₃ = 0. When Δk is small, the total energy and enstrophy are approximately conservative. They are exchanged in basically the same direction as the resonance, but the area of possible non-linear quasi-resonance is much different when compared to resonance, in that more energy is transported from medium wave to long wave, more enstrophy from medium wave to short wave and they exchanged among the three waves. On other hand, the ratio of three areas varies significantly, an indication that in comparison wity resonance there is also considerable change in the relative value of exchange of energy and enstrophy among the three quasiresonant waves.