The purpose of the study was to explore if there was a significant effect on debasing impurity, current and pH value by four common aquatic plants: Taros, Water Hyacinth, Water Spinach, and Water Cabbage. The duration of the experiment was 31 days. The researchers observed and recorded the change of impurity, current and pH value. Furthermore, the researchers utilized MANOVA to analyze the data collected and to explore if there was a significant effect on purifying polluted water by four aquatic plants. According to the results, there was a significant difference on debasing impurity and pH value among the four aquatic plants. These four aquatic plants were able to debase impurity in order as Water Cabbage, Water Hyacinth, Water Spinach and Taros. The effects of debasing impurity were in order as Water Hyacinth, Water Cabbage, Taros, and Water Spinach.