  We have surveyed the central molecular zone (CMZ) of our Galaxy in the CO
J=3-2 line with the Atacama Submillimeter-wave Telescope Experiment (ASTE).
Molecular gas in the Galactic center shows high J=3-2/J=1-0 intensity ratio (~
0.9) while gas in the spiral arms in the Galactic disk shows the lower ratio (~
0.5). The high-velocity compact cloud CO 0.02-0.02 and the hyperenergetic shell
CO 1.27+0.01, as well as gas in the Sgr A region exhibit high J=3-2/J=1-0
intensity ratio exceeding 1.5. We also found a number of small spots of high
ratio gas. Some of these high ratio spots have large velocity widths and some
seem to associate with nonthermal threads or filaments. These could be spots of
hot molecular gas shocked by unidentified supernovae which may be abundant in
the CMZ.
