When a droplet of polymer solution or colloidal suspension is dried up on a substrate, it leaves a dried film on the substrate. This process is important in the inkjet-printing and other related technologies. Though the drying phenomena are seen in our daily life, the process involves many challenging problems in soft matter physics such as convective diffusion in the droplet of soft matter solutions, gelation and solidification, contact line pinning, skin formation and buckling etc. In this talk, I will describe our recent study for these phenomena focusing on the structure of colloidal solution formed after the evaporation of solvent.