The method rising measuring resolution through reducing pitch of the transducer has brought forward from the basic structure, principle and the corresponding relationship among pitches of capacitive electrodes, period T and phase shift of o. But if the traditional technique of PCB made of the transducer is still used, it will meet with difficulties in lead wire. And so the technology transplant from the transducer to grating is presented, the basic principle of the phase modulation grating similar to the transducer is described and the experiments setup of transmitted and reflective grating are put out. Some practical schemes f the new grating with resolution to sub-micron, even nm is given.