Abstract: The nonlinearity parameter is an important indicator of the nonlinear acoustic effect on biological tissues. Compared with linear parameters, B/A has one to two order of magnitude higher sensitivity to the tissue properties. Using B/A as the tomography parameter of biological tissues is more conducive to tissue characterization and medical ultrasound diagnosis. The existing B/A imaging relies on the accuracy of the B/A measurement. In order to obtain a good B/A imaging result, the comparisons of the classical methodologies for B/A parameter measurement based on the finite amplitude methods are carried out, both in computer simulation and phantom studies. The experimental re-sults show that the extended comparative method (ECM) can provide more accurate B/A measurement with the per-centage error less than 3% Combined with filtered back projection, the ECM is implemented to get the B/A tomogra-phy imaging in simulation environment. The B/A tomography validates that the ECM can get the right distribution of B/A for a simple tissue.