The high sensitivity, high operating frequencies (GHz),low power consumption,small size and IC compatible fabrication process of FBAR make this technology ideal for high performance transducers and sensors.FBAR based sensors as,for example,high sensitivity mass sensors,DNA and protein detector,gas sensor, mercury ion detector,and localized mass detector achieve improved sensing performance compared to other MEMS sensor technologies.The primary focus of this paper is to summarize the FBAR sensor technology developments and the investigations of the FBAR high sensitive sensor,FBAR resonant sensor and their high frequencies read out circuit.The original idea which presented here is to achieve the FBAR transducers' resonant frequency shift signal read-out by the six port reflectometer scheme, and to fulfill the FBAR sensors′ monolithic integration with the MMIC or LTCC fabricated six port networks.