High temperature micro pressure sensors were fabricated by using polycrystalline 3C-SiC piezoresistors grown on oxidized SOI substrates by APCVD. These have been made by bulk micromachining under $1{ imes}1mm^2$ diaphragm and Si membrane thickness of $20{mu}m$. The pressure sensitivity of implemented pressure sensors was 0.1 mV/$V{cdot}bar$. The nonlinearity and the hysteresis of sensors were ${pm}0.44%{cdot}FS$ and $0.61%{cdot}FS$. In the temperature range of $25^{circ}C{sim}400^{circ}C$ with 5 bar FS, TCS (temperature coefficient of sensitivity), TCR (temperature coefficient of resistance), and TCGF (temperature coefficient of gauge factor) of the sensor were -1867 ppm/$^{circ}C$, -792 ppm/$^{circ}C$, and -1042 ppm/$^{circ}C$, respectively.