A r t i c l e I n f o A b s t r a c t Keywords:Red galangal, nanoparticles, maceration, ethanol, n-hexane, ethyl acetate, cytotoxic activity, BSLT, LC50Some of the secondary metabolites present in red algae are terpenoids, quinones, flavonoids, alkaloids, essential oils, diarylheptanoids, steroids, cardioglycosides, oils and fats, tannins, carbohydrates. Activity of rhizomes, leaves and flowers red leaf is as antimicrobial, antifungal, anti-oxidants, anti-tumor, anti-cancer and vasodilator. One way to improve the physical, chemical and bioactivity properties of natural compounds was to make them into nanoparticles. In this study, the isolation of bioactive compounds contained in red laos rhizome by maceration method using ethanol solvent was done, then partitioned with nhexane and ethyl acetate. The extracts thus obtained are fabricated into nanoparticles. Extracts in bulk and nanoparticles were then tested for cytotoxic activity using BSLT method.