A wireless passive pressure sensor based on low temperature co-fired ceramic（ LTCC） is designed. The working circuit of sensor is composed of a LC resonant circuit

which consists of an inductor and a capacitor in parallel

and a planar spiral inductor and a parallel plate capacitor is fabricated by thick-film process. The strain characteristic of the sensor is based on the response of resonance frequency of the LC circuit to the applied pressure

and wireless detection is realized by electromagnetic coupling with two inductances. Test results show that the resonance frequency of sensor decreases with the increase of pressure

and response sensitivity of the resonance frequency to pressure is about 331. 70 kHz / bar.