We present a study of the connection between activity of nuclear accretion, star formation, and galaxy morphology. In our work, we focus on mid-infrared selected AGNs, which are complementary samples of X-ray selected objects. We fit optical to far-infrared photometry by the latest SED techniques to derive stellar masses, star formation rates, dust properties, and AGN contribution in the COSMOS field. We explore galaxy morphologies through HST/ACS and HST/WFC3 images, which provide structural properties of galaxy stellar component at high redshift. We discover the differences between obscure AGN host galaxies, unobscure AGN host galaxies, and star-forming galaxies, and discuss the role of AGNs in galaxy formation and evolution.