My research focuses on inflation, including non- Gaussianities, cosmic perturbation theory and inflation models. In the field of non-Gaussianity, we have shown a natural possibility of quasi-local shape non-Gaussanity with continuous squeezed limits. We also calculated the large trispectra for general single field inflation. Using cosmic perturbation theory, we have shown that inflation is UV sensitive to loop corrections. We have also built a few inflation models, such as quasi-single field inflation and multi- stream inflation.