The aim of this study is to investigate the effect of the rock brittleness indexes on the specific ampere draw of the circular diamond saws. In this study, twelve rock types belonging to granite and carbonate rock were cut with two different types of circular diamond saws on a fully instrumented laboratory-sawing rig at different feed rate and depths of cut. Rock samples were collected from factories from Iran for laboratory tests and uniaxial compressive strength and tensile strength were determined. The brittleness of B-1 (the ratio of compressive strength to tensile strength), B-2 (the ratio of compressive strength minus tensile strength to compressive strength plus tensile strength), and B-3 (the area under line in relation to compressive strength and tensile strength) were evaluated. The relations between specific ampere draw and rock brittleness indexes were investigated using simple regression analysis. The results show that, there is no strong correlation between the specific ampere draw values and the brittleness of B-1 and B-2 values in carbonate rocks but there is a strong correlation between specific ampere draw and B-3 while the specific ampere draw values of granite rocks arc strongly correlated with all of brittleness indexes. It was concluded that the specific ampere draw values of granite and carbonate rocks can be reliably predicted by brittleness indexes and brittleness of B-3, respectively.