The cultivation of the sea cucumber Holothuria scabra Jaeger for broodstock and production in captivity at sea with naturally available feed, it was reported that the daily growth rate was slow at 0.14±0.10g day-1 (Jasmadi, 2018). One of the efforts to increase growth is substrate manipulation. Organic material in the form of chicken manure has been applied in this study as a mixed substrate with sand at different percentages. Holothuria scabra This study aims to manipulate Holothuria scabra rearing substrates to increase growth. This study used a completely randomized design (CRD) at a 95% confidence level. The research treatments consisted of treatment A (10% organic matter 80% sand), treatment B (20% organic matter 80% sand), treatment C (30% organic matter) 90% sand), D (without organic matter = 100% sand) (100% sand), each treatment was repeated three times. The results showed that the availability of organic matter in the form of chicken manure at different percentages in the sand substrate had a significant effect on growth (P<0.05), but was not significantly different on the survival rate of Holothuria scabra. The growth of Holothuria scabra were better when organic matter is added than without organic matter content in the form of chicken manure. The difference in the percentage of organic matter affects the fulfillment of energy for nutritional needs, so that the availability of energy for growth is also different, but this difference does not affect Holothuria scabra’ survival rate. The difference in the percentage of organic matter content in the form of less or excess chicken manure has been shown to have a negative effect on growth. Furthermore, it is known that treatment B (20% organic matter in the form of chicken manure and 80% sand) per substrate weight has a better effect on growth compared to other treatments. treatment B (20% organic matter in the form of chicken manure and 80% sand) per weight of substrate can be applied to increase growth Holothuria scabra in rearing substrate manipulation. it is recommended that further research be conducted on the period of addition of organic matter, because there are indications of a decrease in organic matter content during the study.