The present invention is about preparing gelatin nanoparticles having a size of about 200 nm are supported or not supported with a hardly-water soluble drug without a homogenizer by constructing O/W/O or W/O systems, thereby relatively prolonging the circulation time within the human body as compared to a water-repellent particle because it is free from the immune system, and enhancing EPR (Enhanced permeability and retention) effects. In this case, the hardly-water soluble drug includes hardly soluble anticancer agents such as paclitaxel, coenzyme Q10, ursodexoychlic acid, ilaprazole or imatinib mesylate. Furthermore, the O/W/O or W/O systems are nonpolar phase/polar phase/nonvolatile nonpolar phase and polar phase/nonvolatile nonpolar phase systems, respectively. More specifically, the O/W/O or W/O systems presents a hardly soluble drug/gelatin nanoparticle/fatty acid and gelatin nanoparticle/fatty acid systems, respectively.