Arsenic exists in various forms depending on the species different from each other differs not only physic-chemical properties, toxicity and bioavailability, also changes in vivo. Therefore, analysis only the total arsenic concentration is difficult to be trusted and quantification the individual species of the arsenic element is important. The main route of arsenic is exposed to the human body is known in the food intake. The large contribution food to energy intake of Korean is a grain, but grains such as polished rice and unpolished rice contain highly toxic inorganic arsenic. This study sets a chemical species analysis of arsenic in various grains with a high intake frequency of Korean and monitor domestic and imported grain by IC-ICP-MS. First, the extraction method uses the Microwave digestion system Shake, Ultra sonication and extraction solvent (0.28 M HNO3 and water) to compare the extraction efficiency. As a result, the extraction method with Microwave digestion system and 0.28 M HNO3 extraction solvent has the highest extraction rate. Second, extraction temperature was raised from 60℃ to 120℃ by 20℃, and extraction time also change from 30 min to 120 min by 30 min to optimize the preparation conditions of chemical species analysis of arsenic. In conclusion, this experiment sets 70 minutes at 85℃ in the preparation conditions for the arsenic species analysis of grain. This extraction condition applies wheat, unpolished rice, polished rice, glutinous rice. In grain, the arsenic speciation method is suitable for determination of sum of the species of the arsenic (over 90.1 % recovery rate). Inorganic arsenic concentration is 1.55-6.95 μg/kg in wheat and 100.6-110.9 μg/kg in unpolished rice. Polished rice differ content of inorganic arsenic depending on country of origins. The inorganic arsenic range of Korean rice is 49.8-74.1 μg/kg, 49.8-170.4 μg/kg in U.S., 35.8-199.5 μg/kg in China and 53.8-103.8 μg/kg in Australia. Content of inorganic arsenic of glutinous rice is 42.6-53.5 μg/kg. Compared to inorganic arsenic standard of polished rice in China (150 μg/kg), Australia and domestic are suitable, but U.S. (up to 170.4 μg/kg) and China (up to 199.5 μg/kg) are exceeds. Currently, the criteria of arsenic in grain are not established in Korea. Therefore, the setting of the standard of arsenic is necessary for the management imported rice. Considered of difference in toxicity depending on arsenic species, Korea also should make standard of inorganic arsenic in grain like China.