Since the earliest times, the Iranian architecture had been notable for its gorgeous ornamentation carved in stone. However beginning from the VIII-IX centuries, there was a rise in popularity of wood carving, plaster carving, brick ornaments and glazed ceramic tiles. The aim of the study is to compare the motifs of the decor made in different techniques and materials in the Muslim architecture during the period of the VII-XVIII centuries; identify recurring motifs; analyse their symbolic meaning. Scientific novelty of the research lies in studying semantics of architectural monuments. The findings prove that the decor of Iran’s Muslim architecture performs not only a decorative function but also religious-symbolic and worldview ones.