Bipolar molecular outflows have been observed and analyzed with molecular emission lines, Especially, ^(12)CO(J=1→0) has been used to figure out their kinematic structures instead of H₂ molecule owing to the H₂ observational difficulties. Since 1980' s, the wing portions of the observed line profiles of ^(12)CO toward the molecular clouds, which might have been observed as star-formation regions, have been important to explain the dynamical behavior of the molecular clouds, that is, the interaction of the wind type flow from a central IR source with the surrounding molecular clouds. The interaction surely develops the bipolar shaped outflow pattern due to the rotational molecular disk surrounding the central source. The molecular disks have been observed with CS, SO₄ molceular emission lines that are useful to reveal the high density regions in the molecular cloud complexes. IR observations have also found out the existence of the buried central sources and their luminosities. The reversely developed wing portions in opposite regions with respect to the central IR source distinctively show the bipolar-shaped radio lobes, meaning the opposite directed outflows with an average velosity of∼25 ㎞ sec^(-1). Their average size and dynamical time scale are ∼1pc and ∼2×10⁴ yrs respectively. The mass involved in the outflow can be estimated with the aid of ^(13)CO obvervation toward the bipolar outflow regions. These regions have often optical or radio jets inside, sometimes, being related to Herbig-Haro objects and the shocked regions at their ends. The energetics and moments related to the outflows show that the radiative momentum of the central source can not produce the flows unless the radiation interact with the environmental gas many times, and also that they seem to be independent of the dynamical behaviors of the outflow, i.e., the size and the velocity themselves, and only to be dependent on the mass involved the outflows. The occurrance rate of the bipolar molecular outflow is estimated to be∼4×10⁴yr^(-4) kpc^(-1) with their number detected within the 1 kpc solar circle. This shows that the phenomena of the bipolar outflows can be produced in all kinds of spectral type stars, which might approach to the main-sequence in HR diagram. Many theories have been suggested to explain both the dynamics and the energetics of the outflows, being still insufficient. We expect that the molecular line observation with a high angular resolution and the developed theories should figure out the details of the outflows near future.

Sixty-eight open clusters have been sampled in proportion to the age fraction of the number distribution of open clusters in Galaxy in order to find out the aging effect in number density distribution of member stars of the open clusters. The Ring method can be used to establish the number density distribution around the central regions of the open clusters. Their number density distributions have been classified to several types according to their shapes. They have been arranged to a serial distribution of A to F in age.