The aim of this study was to investigate the optimum particle size of rice flour for making rice noodles. Rice noodles were prepared with rice variety such as Milyang 278 because it has 25.4% of high amylose content. The rice grains were pulverized by dry milling and passed through 3 different sized sieves (A: -60 ~ +100, B: -100 ~ +150, and C: -150 ~ +200 mesh). The average particle sizes of A, B, and C were 187.27, 103.79 and 74.88 um, respectively. Rice noodles were prepared at 35% of moisture content, 50/90/90/90°C of barrel temperature, and 200 rpm of screw speed in the twin screw extruder. Textural properties and cooking qualities were evaluated to determine the suitability for making rice noodles. Hardness of the dry noodles prepared with A, B, and C were 2.762, 4.546, and 2.065 N, respectively. Extension (R max) of the cooked rice noodles prepared with A, B, and C were 0.526, 0.857, and 0.534 N while Extensibility (E value) were 15.97, 18.03, and 16.78 mm, respectively. Cooking loss values were 4.47, 2.88, and 2.16%, respectively, while the turbidities of their cooking water were 0.177, 0.073, and 0.088, respectively. As the result the flour passed through -100 ~ +150 meshes was the most appropriate for making rice noodles. Control of particle size in rice flour with high-amylose content can be a useful way for making good quality rice noodles.