The transverse shrinkage behavior of early wood and late wood tracheids of radiata pine (Pinus radiata D. Don) was investigated by the power spectrum analysis. The representative cell model shapes before and after shrinkage constructed by the analysis revealed that the early wood tracheid showed anisotropic shrinkage, although the late wood tracheid showed almost isotropic shrinkage. To link the macroscopic shrinkage of coniferous wood with the results obtained by the power spectrum analysis, a two-layer model composed of early wood and late wood was adopted, and the relation between shrinkage anisotropy and late wood fraction was predicted. The results suggested that the shrinkage anisotropy depended significantly on the mechanical interaction between early and late wood.