  The lifetime of mm size dust grains, such as chondrules, in the nominal solar
nebula model is limited to $\sim 10^{5}$ yr due to an inward drift driven by
gas drag. However, isotopic and petrological studies on primitive meteorites
indicate a discrepancy of $\gtrsim 10^{6}$ yr between the formation time of
chondrules and that of chondritic parent bodies. Therefore chondrules should
survive for $\gtrsim 10^{6}$ yr in the solar nebula against the inward drift
without subsequent growth (i.e., planetesimal formation). Here we investigate
the conditions of the solar nebula that are suitable for the long lifetime of
chondrule-sized dust particles. We take the turbulent strength, the radial
pressure gradient force, and the disk metallicity of the solar nebula as free
parameters. For 1 mm-radius-chondrules to survive and keep their size for
$\gtrsim 10^{6}$ yr, the suitable condition is a weak turbulence ($\alpha \sim
10^{-6}$), a flat radial profile ($\eta \lesssim 10^{-3}$), and a high
metallicity ($Z\sim 0.1$). This condition is qualitatively consistent with the
characteristics of protoplanetary disks suggested by recent observations. We
eventually propose that planetesimal formation may be induced by the disk
evolution, e.g., the inside-out dispersal of the gas component due to the disk
wind.
