Transient elastography can be used to measure the viscoelastic properties of soft tissues using a simple inverse problem approach. However, there is measuring bias in this method due to several factors, e.g. radius of disk load and nearfield effect is the main reason for overestimating the shear velocity, and diffraction effect leads the measurement of shear attenuation to be overestimated. A self-adapting method is proposed to correct both the shear velocity and attenuation biases in our study. Theoretical and experimental results are in good agreement, and this new method is proved to be an effective way to correct the viscoelastic properties bias measured by transient elastography.