Abstract: Leaching of gold is a nwe method for non-cyanidation leaching gold.Experiments of roasting the carbonaceous primary gold ore that connot be treated with flotation and the affecting factors of iodide leaching glod are intrduced in this paper.In the Experiments,many experimental phenomenon have been analyzed and the results are gotten out that the logical temperature of roasting ore is 650℃,the leaching rate of gold can be increased 15 percent and the leaching velocity is higher than other methods.