Abstract: The thin films of silicon nitride were prepared on the quartz substrate by PECVD.The fixed-fixed nitride beams were fabricated using MEMS process.The nanoindentation measurement showed that Yang’s modules of nitride thin film was 136~172Gpa.The residual stress was obtained by wafer-curvature measurement method to evaluate the spring constant of nitride beam.The spring constant of the beam was ranging from 11.4 to 57 N/m.The actuated voltage was derived from 32.8 to 73V according to the spring constant.The actuated voltage of the beam was measured from 34 to 60V.