Abstract: Many inverse parameters result in problems such as non-uniqueness and unstability in 3-D resistivity inversion.The 3-D resistivity inversion for minimum stricture using conjugate gradients shows good results as compared with traditional inversion method of least squares. We also studies how the initial model and data errors influence the results of 3-D inversion in this paper, in order to investigate stability and reliability of the 3-D inversion method.