We carried out CO survey toward IR-excess clouds using SRAO 6-m telescope in search of molecular H2. These clouds, which show far-infrared excess over what is expected from HI column density, are considered to be candidates of molecular clouds. In order to find new high Galactic latitude clouds, we made mapping observations for 14 IR-excess clouds selected from Reach et al.(1998) in 12CO J = 1 - 0 line, supplementing the similar survey in southern hemisphere (Onishi et al. 2001). 12CO emission is detected from three IR-excess clouds among 14 objects. Three newly detected clouds exhibit somewhat clumpy morphology and column densities amount to ~ 1021 cm-2. One of three clouds, DIR120-28, show discrepancy between IR-excess center and CO emission center. It seems that IR-excess may not be an effective tracer of molecular gas. Instead, optical depth(τ) excess, i.e., IR-excess corrected for temperature dependence, may be more effective tracer of molecular clouds, since, by combining statistics from both hemispheres, we found that the detection rate is higher for IR-excess clouds with lower dust temperature.

In an attempt to investigate star formation activity and statistical properties of clumps of high Galactic latitude clouds (HLCs), we mapped the Polaris Flare region, PF121.3+25.5, in 12CO and 13CO J = 1 - 0 using SRAO 6-m telescope and also observed its 12 13CO peak positions in CS J = 2 - 1 with TRAO 14-m telescope. 13CO integrated intensity map shows clearly its clumpy structure and the locations of clumps well agree with 12CO morphology. CS line is not detected toward the 12 13CO peak positions, so we can conclude there are no dense (~ 104 cm-3) in this region. We decomposed 105 clumps from 13CO map using GAUSSCLUMPS algorithm. The mass of clumps ranges from 7.8 M⊙ to 7.4x10-2 with a total mass of 66.4⊙ The mass spectrum follows a power law, dN/dM ∝ M-α with a power index of α =1.91 ± 0.13. The virial masses of clumps are in the range of 10 ~ 100 and so these clumps are considered to be gravitationally unbound.