I am mainly working on particle cosmology. In particular, I am interested in inflation cosmology, baryogenesis and axion cosmology. The inflationary universe can not only solve cosmological problems such as the horizon problem but also produce primordial density perturbations which are perfectly consistent with anisotropies in the cosmic microwave background radiation observed by WMAP and Planck. Now inflation is a new paradigm of cosmology. I have been studying inflation models in supergravity and obtaining constraints on the reheating temperature after inflation by considering the cosmological effects of gravitinos which are predicted in supergravity.Since inflation dilutes away pre-existing matter, the baryon number and dark matter should be produced after inflation. I am working on the Affleck-Dine baryogenesis in supersymmetric theories and Q-balls which are non-topological solitons produced in the Affleck-Dine mechanism. I am also studying the cosmological consequences of axions which are a promising dark matter candidate.