Abstract: Ill-posed problem often appears in the inverse problem in geophysics. Many regularization methods are used to produce reasonable solutions. Among them, Tikhonov regularization and truncated SVD (Singular Value Decomposition) are two important methods used widely, but how to compare them is a challenging and meaningful area under discussion. The paper discusses the comparison between them. First, with the SVD of coefficients matrix, the ordinary least squares (LS) solu