Transformers have an important place in electric transmission and distribution systems. Transmission and distribution efficiency of transformers should be high in regard to energy efficiency. Efficiency is one of important parameters of transformers like every electric machine. Transformers are highly efficient because they do not have any moving parts, but a very small air gap. When alloys of different materials are used to increase efficiency of transformers, core loss shows differences. The present study aims to examine how core losses and efficiency are affected when M85-23P, M120-27S, M105-30P sheets, which are used in the production of core of transformers in industry, and amorphous materials, which have been started to be produced recently, are used in the core of dry type distribution transformers. Besides, it is aimed to compare these sheets in terms of cost and manufacturing in this study. For this purpose, a 100 kVA dry type industrial distribution transformer with various materials was analyzed by Ansys Maxwell package program and the results were compared.