  We performed single point [C I] $^3$P$_1$-$^3$P$_0$ and CO J=4-3 observations
toward three T Tauri stars, DM Tau, LkCa 15, and TW Hya, using the Atacama
Large Millimeter/submillimeter Array (ALMA) Band 8 qualification model receiver
installed on the Atacama Submillimeter Telescope Experiment (ASTE). Two
protostars in the Taurus L1551 region, L1551 IRS 5 and HL Tau, were also
observed. We successfully detected [C I] emission from the protoplanetary disk
around DM Tau as well as the protostellar targets. The spectral profile of the
[C I] emission from the protoplanetary disk is marginally single-peaked,
suggesting that atomic carbon (C) extends toward the outermost disk. The
detected [C I] emission is optically thin and the column densities of C are
estimated to be <~10$^{16}$ cm$^{-2}$ and ~10$^{17}$ cm$^{-2}$ for the T Tauri
star targets and the protostars, respectively. We found a clear difference in
the total mass ratio of C to dust, $M$(C)/$M$(dust), between the T Tauri stars
and protostellar targets; the $M$(C)/$M$(dust) ratio of the T Tauri stars is
one order of magnitude smaller than that of the protostars. The decrease of the
estimated $M$(C)/$M$(dust) ratios for the disk sources is consistent with a
theoretical prediction that the atomic C can survive only in the near surface
layer of the disk and C$^+$/C/CO transition occurs deeper into the disk
midplane.
