Antioxidant activity and identification of antioxidative compunds of Callyspongia sponge from Seribu Islang (Kepulauan Seribu) were investigated. The sponge was extracted with acetone and the extract was concentrated using rotary vacuum evaporator. DPPH and tiocyanate methods were used to examine the antioxidant activity of the extract. The extract strong antioxidant activity in DPPH mehod with IC of 41.21 g/ml. Chemical analysis indicated that the antioxidative compund in the sponge was alkaloid group.
