Water hyacinth or Eicchornia crassipes is a free-floating aquatic plant and is easily found in swamps or rivers. The rapid growth of water hyacinth can disrupt the aquatic environment, thus water hyacinth is categorized as one of the world’s worst weed. The challenge is not on how to eliminate the number of this weed, but on how to take advantage by the presence of this water plant. Water hyacinth is known to contain high phenolic content and antioxidant activity. Water hyacinth was extracted using 96% ethanol/water with mass to solvent ratio of 1:30 at 3 different temperatures (30°C, 40°C, 50°C). Spray drying was conducted to produce extract powder with the addition of maltodexrin and Arabic gum as the encapsulating agents. The stability of liquid and powder extract was compared based on the Total Phenolic Content (TPC) and antioxidant activity. The highest TPC was obtained from extraction at 30°C whereas the highest antioxidant activity was obtained from extraction at 50°C. In powder extract, the highest TPC and antioxidant activity was obtained from powder with ratio 2:1 of TSS to encapsulating agents. The stability was performed under different storage conditions. The degradation of TPC was faster in room temperature.