Superconducting quantum Interference devices (SQUIDs) are the most sensitive detector of magnetic flux.For a comprehensive review of superconducting Josephson junctions and SQUIDs,please refer to references [1-4].Biomagnetism involves the measurement and analysis of very weak local magnetic fields of living organ and various in humans.In this paper,we report the SQUID-based biomagnetic applications in the low field nuclear magnetic resonance imaging (MRI),magnetocardiography,magnetically labeled immunoassay and MRI with the magnetic nanoparticles injection.The state of art in the high-To SQUID-based low field MRI is addressed.We designed a low field nuclear magnetic resonance (NMR) spectrometer by using a high-Tc SQUID and superconducting can for optically pumped hyperpolarized 3He gas to improve the NMR performance.Low field MRI is promising for the future biomagnetic applications.