Abstract: Performance of MEMS device is mainly decided by fabrication process.In this paper,a kind of 2-D microaccelerometer with complex microstructure is designed and the effect of fabrication characteristic on performance is investigated,including mass eccentricity,beam’s fabrication error,nonsymmetrical effect and non-parallel effect.It is found that mass eccentricity only influences the angle displacement but has no effect on main-axial stiffness and output of sensor.Moreover,the influence of beams’ thickness error can be ignored while the beams’ width error need to be controlled.And the nonsymmetrical structure has some effect on the performance.The more nonsymmetrical the structure is,the more high the transverse sensitivity is.Furthermore,the non-parallel effect cause the axial displacement under the same load to be decreased while the sensitivity to be increased.