Abstract: Aiming at the problem that the process is complex and the working volume is large in measurement of the trajectory of borehole by using the widely used all azimuth inclinometer, the storage inclinometer while drilling has been developed. The inclinometer consists of wellhead monitor and probe, can be used to measure without cable the inclination while drilling in horizontal or directional boreholes, to measure and record the dip and the azimuth in drilling direction. The monitor works synchronously with the probe to record the depth of borehole. When drilling is finished, the monitor shows 3D drilling trajectory.