Naturally, seaweed Gracilaria lives on various aquatic substrates including sandy, mud, coral and coral fragments, but scientific information that reveals the extent to which substrates influence the growth of this type of seaweed in cultivation has not been widely studied. The aim of this research is to determine the type of substrate that influences the growth of seaweed G. verrucosa, and to determine the best substrate for seaweed G. verrucosa. Collecting samples of seaweed G. verrucosa in the waters of Kalumata Ternate for 5 days. The cultivation process in a controlled container was carried out at the Unkhair Integrated Laboratory UPT, Sasa Village for 45 days. The overall research implementation time is 50 days from May – July 2022. The results of the research showed that the composition of the substrate type had a very significant effect on the absolute weight growth and relative growth of the seaweed G. verrucosa. The type of coral fragment substrate had the best influence on absolute weight growth with an average value of 57.33 grams, followed by sandy substrate at 37 grams, and the lowest was muddy substrate at 30.66 grams. The coral fragment substrate also had the best influence on relative growth at around 8.991%, and the lowest was found on the muddy substrate at around 7.593%.