  The formation and early evolution of low mass young stellar objects (YSOs)
are investigated using three-dimensional non-ideal magneto-hydrodynamics
simulations. We investigate the evolution of YSOs up to ~ 10^4 yr after
protostar formation, at which protostellar mass reaches ~ 0.1 M_\odot . We
particularly focus on the impact of the dust model on the evolution. We found
that a circumstellar disk is formed in all simulations regardless of the dust
model. Disk size is approximately 10 AU at the protostar formation epoch, and
it increases to several tens of AU at ~ 10^4 yr after protostar formation. Disk
mass is comparable to central protostellar mass and gravitational instability
develops. In the simulations with small dust size, the warp of the pseudodisk
develops ~ 10^4 yr after protostar formation. The warp strengthens magnetic
braking in the disk and decreases disk size. Ion-neutral drift can occur in the
infalling envelope under the conditions that the typical dust size is a \gtrsim
0.2{\mu}m and the protostar (plus disk) mass is M \gtrsim 0.1 M_\odot. The
outflow activity is anti-correlated to the dust size and the strong outflow
appears with small dust grains.
