Nano Drug Delivery System (nano-DDS) is a new medical technology. We studied medical use used by about 7 [nm] ferromagnetic fluids. We searched good energy condition offerrofluid contrast medium radiograph image used by SPring-8 synchrotron radiation X-ray. As results, in case of low photon energy 15.0 [KeV] (λ = 0.8 Å). We showedferrofluid in Acryl amid gel and taro leaf and mugwort. #1. We found Low photon energy could show vascular tissue and ferrofluid distribution respectively. In case of medium photon energy 20.0 [KeV] (λ = 0.6 Å). We observed ferrofluid in rat ear lobe and rat stomach and rat foot. #2. We found medium photon energy could see several organizations by changing exposure. In case of high photon energy 25.0 [KeV] (λ = 0.5 Å). We showed ferrofluid in chicken egg and pork. #3. We found high proton energy was suitable for observing ferrofluid distribution in plain organization, but was not suitable for observing ferrofluid distribution in complicate organization.