The ornaments of Rumah Bolon (literally means ‘big house’), or RB for short, in Pematang Purba, Purba Subdistrict, Simalungun Regency have cultural meanings and tend to show the characters of family, traditional figures and Simalungun society. With the discussion using semiotic study, the purpose of this research is to find out the form, function and meaning of RB’s ornaments. The study is to find out assumptions that can be developed for future generations and to preserve the prevailing norms. The research used library, observation, and interview methods was helped by semiotic theory proposed by Zoest and Peirce. The results show that the RB’s ornaments consist of of bohi-bohi (face), suleppat, hambing mardongan (fighting goats), jombut uwou, ipon-ipon, morodor porkis, bodat marsihutuhan, hail putor, pahu-paku patundal, bindu matoguh, gatip-gatip, andor ni tabu mangganupi desa, boras pati, rumbuk sinandei, tanduk horbo, silobur pinggan, appul-appul, bunga sayur matua, rumbuk-rumbuk sihala, bunga hambili, palit, tali simuor-muor, bunga bongbong, sisik ni tanggiling, paria-paria, harungguan, simaronong-onong, andor hadukka, bunga tarompet, sulih ni rotak, limut ni tao, horis ni hotala, bulung ni anduhur, and gundur manggolapa.