Abstract: The relationship of the yield strength and elongation with thickness and width was studied through tensile testing of micro-sized H62 copper alloy foil specimens.The results show that the yield strength of the alloy foils decreased with the decrease of thickness firstly,while the yield strength increased when the thickness was less than 250 μm.With the decrease of section width,the elongation of the specimens decreased.When the thickness was reduced from 500 μm to 50 μm,the elongation increased firstly and then decreased,the maximum value was obtained at the thickness of 250 μm.