  We study the dust motion at the surface layer of protoplanetary disks. Dust
grains in surface layer migrate outward due to angular momentum transport via
gas-drag force induced by the stellar radiation pressure. In this study, we
calculate mass flux of the outward motion of compact grains and porous dust
aggregates by the radiation pressure. The radiation pressure force for porous
dust aggregates is calculated using the T-Matrix Method for the Clusters of
Spheres. First, we confirm that porous dust aggregates are forced by strong
radiation pressure even if they grow to be larger aggregates in contrast to
homogeneous and spherical compact grains to which efficiency of radiation
pressure becomes lower when their sizes increase. In addition, we find that the
outward mass flux of porous dust aggregates with monomer size of 0.1 $\mu$m is
larger than that of compact grains by an order of magnitude at the disk radius
of 1 AU, when their sizes are several microns. This implies that large compact
grains like calcium-aluminum rich inclusions (CAIs) are hardly transported to
outer region by stellar radiation pressure, whereas porous dust aggregates like
chondritic-porous interplanetary dust particles (CP-IDPs) are efficiently
transported to comet formation region. Crystalline silicates are possibly
transported in porous dust aggregates by stellar radiation pressure from inner
hot region to outer cold cometary region in the protosolar nebula.
