Abstract: The comprehensive application of PET/CT has powerfully promoted the development of nuclear medicine.Compared with CT,MRI can obtain images with higher soft-tissue contrast,better spatial resolution without ionizing radiation.The research of PET/MRI has become a hot topic and get some breakthroughs in recent years.Although the extensive use of PET/MRI still has some difficult,the existing research achievements have demonstrated the extensive room for progression.PET/MRI has capacity to bring molecular imaging into a new era.