  We have examined trapping of two-armed nearly vertical oscillations in
polytropic disks. Two-armed nearly vertical oscillations are interesting in the
sense that they are trapped in an inner region of disks with proper
frequencies, if the inner edge of disks is a boundary that reflects
oscillations. The frequencies of the trapped oscillations cover the frequency
range of kHz QPOs to low frequency QPOs in LMXBs, depending on the modes of
oscillations. Low frequency trapped oscillations are particularly interesting
since their trapped region is wide. These low frequency oscillations are,
however, present only when $\Gamma(\equiv 1+1/N)$ is close to but smaller than
4/3 (when spin parameter $a_*$ is zero), where $N$ is the polytropic index. The
above critical value 4/3 slightly increases as $a_*$ increases.
