An accurate four-line ac electrical resistance measurement (ERM) apparatus was devel-oped. By using the ERM the crystallization kinetics of amorphous Nis0P20, FeZr2, Fe86B14 alloys wereinvestigated. The experimental results show that the ERM can identify the early stage of crystallizationin amorphous alloys. The ERM detects a crystallization temperature range obviously wider than theDSC does, indicating that the ERM is more sensitive to the structure evolution in crystallization. Forthe eutectic or polymorphic crystallization, three distinct processes can be identified from the measuredresistance variation: (i) crystal nucleation, (ii) subsequent growth of crystal nuclei, and (iii) coarsen-ing of the crystallites. In the early stage of the primary crystallization, the ERM results reflect the nucle-ation information as well.