In this work, rapidly quenched amorphous cobalt-based ribbons with a metalloid content of 20% and the finemet type ribbons were investigated in as-quenched state. Their structure, magnetic properties magnetoimpedance (MI) behaviour were discussed in the context of the effective magnetic anisotropy peculiarities depending on the length of the ribbons. The experimental results and the results of the finite element model (FEM) calculations for MI were comparatively analyzed. A quantitatively higher magnetoimpedance effect was observed for FEM modeling case, due to the absence of contributions from surface anisotropy, anisotropy distribution and magnetostriction. The results of modeling and experimental studies were in qualitative agreement. Expected change in the type of the field dependence of the MI ratio from one-peak to two-peak was observed. The effective value of the anisotropy field was estimated by fitting the results of the experiment and modeling.