The growing interest in using aquatic plants as immunostimulants has increased world-wide because of the easy preparation, low cost, and few side effects on organisms and environment. Many more uses of aquatic plants discovered by indigenous people in countries, and moreover, a wide range of plants such as herbs, spices, seaweeds, herbal medicines, herbal extracted compounds, traditional Chinese medicines, and commercial plant-derived products has been studied in various aquatic animals. The doses and long-term administrations of immunostimulant don't reveal dose- dependent to enhance or inhibit immune responses directly, and might show negative feedback on immune response to a previous even a reduced condition. The water hyacinth, Eichhornia crassipes was an invading species and extremely caused serious ecological, economic and social problems in Taiwan. The present review presents a potential strategy to minimize the impact of water hyacinth and bring contribution to aquaculture industry.