Last 5~6 years have been a period of revival of PET scanner and PET became an indispensible imaging tool for diagnosis of tumors and other metabolic abnormalities as well as brain chemistry and functional studies.On the other front, we also witness substantial progresses in ultra high resolution MR imaging using UHF MRI such as 7.0T.Based on these two, we have developed a PET-MRI system using an ultra high resolution PET, the HRRT (High Resolution Research Tomography) and an Ultra-High Field MRI, the 7.0T for the molecular fusion imaging at highest level of resolution and sensitivities current technology can offer.This PET-MRI now began provide many new information hitherto unavailable in structures and functions of our human brain, at least in primary level, suggesting that in near future we can extend the technology to the more higher level such as cognitive study.Some results obtained from this new PET-MRI fusion imaging system will be demonstrated and future plans with this new PET-MRI will be discussed.