This paper presents a structural improvement method for temperature coefficient of resonance frequency (TCF) in resonant silicon sensors. A silicon resonator, whose mass was suspended by a slanted flexible beam, was adopted in this study. The slanted suspension beam was formed by (1 0 0) and (1 1 1) crystal planes and fabricated by anisotropic wet etching. We propose a stress buffer structure to improve the robustness of resonance frequency against temperature variations. Theoretical considerations of the tested resonator are proposed to augment the effect of the buffer structure. The temperature dependence of the resonance frequency is experimentally characterized over the range to 60°C. The TCF of the original resonators with no stress buffer structure was linearly fitted to be 36 and . After using an appropriate stress buffer structure, the TCF is linearly fitted to be and . The experimental results suggest that the TCF of the resonator is improved to level by using a stress buffer structure, which has more than an order of magnitude improvement comparing to the original one. The small range of TCF is much more convenient to be compensated by electrical ways.