An aromatic variety, Khao Dawk Mali 105 (KDML 105), is one of the most important varieties of rice in Thailand. However, the increase of production is limited by adverse environmental conditions. As a result, varieties different from KDML 105 are often marketed under the name of KDML 105. Therefore, an efficient and objective method of cultivar identification is urgently needed. Molecular marker techniques based on the polymerase chain reaction (PCR), have provided objective methods of identification. To apply this technique to milled rice, high quality DNA from a single grain of milled rice is needed. DNA extraction method presented here is based on a freeze-and-thaw cycle that enables to extract purified high molecular weight grain DNA without the use of expensive equipment and/or time-consuming procedures. Microsatellite analysis method for cultivar identification was used for extracted DNA. The author analyzed rice samples obtained from Bangkok, Suwannaphum, and Kuala Lumpur markets, and selected varieties different from KDML 105 in Bangkok and Kuala Lumpur market rice samples. By this extraction procedure, we were able to obtain DNA for microsatellite analysis within 2hr and identification required 6hr in total.