X-ray CT scanners are able to measure density distributions in materials without destruction. Since removal of binder causes density change, debinding behavior for alumina powder compacts was evaluated using one of the scanners. In the thermal debinding processes for these compacts, the decrease in average CT value, which corresponds to the overall decrease in X-ray energy penetrated through a compact, was found to be proportional to the decrease in density. The coefficient between the average CT value change and the decrease in density was unique under deferent debinding temperatures and deferent density distributions. Therefore, the binder losses in each cross section in compacts can be estimated by measuring changes in CT value of each section. Thus the binder losses in compacts which had density deference in the axial direction were examined. It was revealed that in the case that a compact is placed with higher density in an upper portion while debinding, the binder loss in a lower portion tends to be less than the other cases.