Background, Motivation and Objective Shear wave elasticity imaging (SWEI) can measure tissue stiffness, which contribute to the assessment of various diseases. The key challenge of SWEI is the shear wave tracking algorithm, where normally the Loupas 2D autocorrelator is used. The Modal Assurance Criterion (MAC) is a statistical quality assurance indicator which is essential to recognize the similarity of varied modal vectors and most sensitive to the largest difference between the comparative values. In this paper, we applied MAC method to track the propagation of the shear wave, which is effective and stable. And we also will use GPU to accelerate (e.g. CUDA) our algorithm in the near future.