ABSTRACT”Magnetics sensors” are the key devices to establish intelligent electronics measurement and control systems for development of high level factory automations ( FA ). Various magnetics sensors having quick response, high sensitivity and robustness have been widely developed in these years using amorphous magnetic alloys, magnetoresistive ( MR ) elements, soft ferrites, and high temperature superconductors. These high-performance sensors are spreading in use in the fields of Power-Electronics ( Power Magnetics ), Mechatronics, Medical Electronics ( Medical Magnetics), Information Apparatus, Security Electronics ( Security Magnetics ) etc..Relations between new magnetic materials and high-performance sensors are summarized and a principle for constitution of these sensors is proposed.