Procedures for analyzing the internal stresses in powder compacts during sintering are reviewed. Sintering properties of powder compacts are taken into account in the macroscopic, component level analysis through a constitutive model, which is for compressible viscous bodies with the driving force of sintering, that is, the sintering stress. Although the fundamental nature of the sintering stress as well as the viscosity can be drawn by using microscopic model of sintering, the exact values for actual powder compacts should be measured by experiments. As an example, sinter-compression tests for metal/ceramic powder compacts are demonstrated in this review. The stress analysis of metal/ceramic graded powder compacts is also presented, and a method of suppressing surface cracks with modification on the sintering properties is described.