Pathological studies of FAP showed that TTR amyloid demonstrates organ and tissue tropism, and therefore, the mechanism of TTR fibril formation is thought to be closely related to the microenvironment in which amyloid fibrils form. However, many key issues, including the precise site of amyloid fibril formation and the effect of amyloid deposition on cells and tissues, remain largely unknown. In this study, we analyzed the relationship between amyloid fibril formation and extracellular matrix. Histopathological analyses showed an increase in the amount of the major components of the extracellular matrix with TTR amyloid deposition. In vitro studies also showed that TTR aggregates had a bioactivity to induce up-regulation of these extracellular matrix components. To know the precise mechanism of this up-regulation may lead to deeper understanding of FAP pathogenesis.