Abstract: Attenuated traveltime tomography is an efficient method for Q estimation, and the calculation accuracy of attenuated traveltimes is essential.An improved attenuation traveltime tomography method is proposed.The proposed method improves the calculation accuracy of attenuated traveltimes for model data, and the picking accuracy of attenuated traveltimes for field data.Considering various properties of seismic rays in different directions, the method defines the direction gradient in ray-tracing instead of the conventional velocity gradient.The calculated reflection angles and ray paths are more accurate, thus more accurate Q results could be obtained.Log spectral ratio inversion is designed for field data attenuation traveltime calculation.Reflections of multi offset traces are used for attenuated traveltime estimations of multi offset traces simultaneously.This method could avoid artificial error by manually selecting optimistic frequency band, and so can derive more robust results.In addition, the method can avoid the effect from overburden by considering the traveltime difference between different layers.Synthetic and field data tests demonstrated that Q estimation using the proposed method is more accurate, and that the migration profile after Q compensation is more reliable, compared with the conventional method.