Theoretical and experimental investigations were made of the effect of a stimulated light pressure on a beam of Na atoms. Expressions were obtained for the force exerted by this pressure on a twolevel atom in the field of counterpropagating short light pulses of arbitrary area and also for the coefficient of pulsed diffusion of atoms in the case of square-wave light pulses. It was found that the value of this force close to the ideal case of square-wave pulses can be achieved in the case of counterpropagating amplitude-modulated waves, ie, two standing waves of different frequencies, which is more convenient from the point of view of experimental implementation. An experimental study was made of the effects of a light pressure force in the field of two standing waves exerted on Na atoms in a beam.