Abstract: 　Magnetic resonance imaging (MRI), featuring as no ionizing radiation, higher soft tissue resolution and multiplanar imaging, has been widely used in the diagnosis of pediatric tumors. Conventional MRI techniques mainly provide information on morphological information of tumors but cannot display physiological and pathological changes in tumors. In recent years, with rapid development of MRI hardware and software, some functional MRI technologies have been applied in clinical practice and have become an important trend on pediatric oncology. These techniques include perfusion-weighted imaging, diffusion-weighted imaging, magnetic resonance spectroscopy, susceptibility weighted imaging. These new technologies can demonstrate the microstructural information of tumors, which will provide more helpful information for diagnosis, treatment and follow-up in pediatric tumors when combined with conventional MRI techniques.