For the past decades, Ethanol has played the main part in the world energy. And the main source of ethanol, the product of yeast fermentation by converting glucose into alcohol, is tapioca, which has put this plant in high-demand, and, consequently, high prices. Therefore, this project work was created in order to conduct feasibility study of using water hyacinth as supplementary source for ethanol production. The ethanol fermentation was processed by adding Saccharomyces Cerevisiae yeast into the water hyacinth, and ethanol measurement was conducted. It was found that the level of ethanol reached the maximum at 0.90 ml. of ethanol for 20 gram of water hyacinth (dry weight). Purity of the distilled ethanol derived from water hyacinth was determined by Semimichro method and the result was distilled ethanol had a boiling point at 79.50 Celsius degree and approximate to the boiling point of 95% ethanol.