Abstract: In the large-scale motion of the atmosphere there is a so-called geostrophic adaptation.This paper demonstrates that there is also a process of adaptation between the pressure and the wind field in the meso- and small-scale motion.From the scale analysis it is found that on the average in the equation of motion the term of the time derivative is one order of magnitude smaller than the main terms in the meso- and small-scale motion.Therefore it may be concluded that the motion of these scales also proceeds slowly under the condition of quasi-balanced forces just as that the large-scale motion proceeds quasi-geostrophically.If,however,in some way this quasi-balanced condition is disturbed,there must be a mechanism to bring the motion back to the quasi-balanced state.For the meso- and small-scale motion the inertia force (velocity advection),the coriolis force and the force of pressure gradient are in quasi-balanced state.