The paper is concerned with sensitivity analysis of a rotational motion sensor thad uses Coriolis effect and a vibrating quartz tuning fork to sense angular rate. The finite element model is employed to both studying the measurement performances of the system and appreciation of the sensitivity of these to the various influencing effects. The performance of computations has been enhanced by means of the dynamically reduced model based on truncation of dynamic contributions of higher modes of a non-rotating structure. The indeterminacy of measurement results due to the change in dynamic properties resulting from the deviations of resonance frequencies caused by geometrical errors has been studied. The sensitivity functions have been derived by using the gradient technique basing upon the finite element model.