The research of ultracold atom produced by laser cooling has been a great success in the past decade. Beyond atomic physics, it has also drawn strong impacts to many other fields, such as condensed-matter physics, plasma physics, quantum information science, and chemistry. The development of a general cooling method to produce ultracold molecule will enrich the ultracold world. Our research interest is the studies of ultracold molecule. We plan to produce cold molecules by molecular beam collisions. And then transfer the cold molecules to a trap and explore a way to reach the ultracold regime (sub-mK). Possible schemes include cavity laser Doppler cooling, sympathetic cooling with laser-cooled atoms, and evaporative cooling. With the ultrcold molecules, we plan to study the ultracold collisions and reactions. For dipolar molecule, the dipole-dipole interaction will provides rich quantum phenomenon in ultracold regime. The interaction can also be tuned by static electric or magnetic field. This will greatly expand the broader of condensed-matter physics studies using ultracold atomic gases. In the future, we also plan to explore the possibility to realize quantum computation by ultracold, dipolar molecule.