Physicochemical properties of crystalline-structured buckwheat starches cultivated and harvested in Taiwan, China, Korea, and USA were compared. X-ray diffraction pattern showed that all starches were type A as are most natural starches. Moisture contents of starches were 6.30-9.58%, and crude protein contents of Taiwanese and Chinese buckwheats were higher than those of Korean and American ones, whereas Korean and Chinese buckwheats had higher fat contents. Blue-value of Chinese buckwheat was highest at 0.39 and that of Korean buckwheat was lowest at 0.32. Amylose content of American buckwheat was highest at 27.6 and that of Korean buckwheat was lowest. Highest water-binding capacity was shown in Taiwanese buckwheat and lowest in American one. Higher amylase contents in Chinese and American buckwheats reduced expansion and solubility. Highest values of viscosity measured by RVA, breakdown indicating process stability, and setback closely connected to retrogradation of American buckwheat resulted in relatively hard gel.