The crystallinity of grains and grain boundaries were evaluated quantitatively by analyzing the quality of Kikuchi lines obtained from the conventional EBSD analysis. A grain boundary was defined as a transition area between nearby two crystals in polycrystalline materials, in which the order of the atomic alignment was degraded by various defects such as vacancies, dislocations, impurities, strain, and so on. The position of the grain boundary was detected by CI (Confidence Index) value and the order of the atomic alignment was evaluated by IQ (Image Quality) value obtained from the EBSD analysis. The crystallinity defined by the IQ value is independent of the density of dislocations and the crystallographic orientation f the grain boundary. The strength of the grain boundary can be analyzed by the IQ value.