Abstract
We investigate the relationship between host galaxies' stellar content and active galactic nuclei (AGNs) for optically selected QSOs with z < 0.5. There is a total of 82 QSOs that we select from the Sloan Digital Sky Survey. These 82 QSOs have both Wide-field Infrared Survey Explorer data and measurable stellar content. With the help of the stellar population synthesis code STARLIGHT, we determine the luminosity fractions of AGNs, stellar population ages, and star formation histories (SFHs) of host galaxies. We find that there is a correlation between the SFH and AGN properties, which suggests a possible delay from star formation to AGN. This probably indicates that the AGN activity correlates with the star formation activity, which consistent with a coevolution scheme for black hole and host galaxies.