One type of seaweed that has good potential and often found in the waters of Indonesia is Eucheuma spinosum (including red algae) which can produce karaginan. Karaginan is a complex mixture from several polysaccharides. In this study, aiming to get the best extraction time and temperature in the product of karaginan from Eucheuma spinosum. Variables used, extraction temperature: 60, 70, 80, 90 (0C) and extraction time: 0.5, 1, 1.5, 2, 2.5 hours. The solvent used, is water and the extraction pH is 8, the ratio of solids solvent: 1: 20 (= 30 g of seaweed: water = 600 mL). From the research results obtained the best persetage of yield at the time 2.5 hours and the temperature 90 ° C, at which in extracted karaginan this condition have yield of 33.0080%.