  We investigate the dynamic evolution of the radiation forces produced by the
pulsed Gaussian beams acting on a Rayleigh dielectric sphere. We derive the
analytical expressions for the scattering force and all components of the
ponderomotive force induced by the pulsed Gaussian beams. Our analysis shows
that the radiation force, for both the transverse and longitudinal components,
can be greatly enhanced as the pulse duration decreases. It is further found
that for the pulse with long pulse duration, it can be used for the stable
trapping and manipulating the particle, while for the pulse with short pulse
duration it may be used for guiding and moving the small dielectric particle.
Finally we discuss the stability conditions of the effective manipulating the
particle by the pulsed beam.
