Abstract: In present study，artificial light was used for adding light to Ceratophyllum demersum，the decolorization of acid dye wastewater by the method and the enzymes response of the plants has been studied． The results showed that Ceratophyllum demersum had high color removal efficiency，and artificial lights added could advance its rate，of which the red light achieved more effect than the white and blue． Apart from that，light intensity and illumination time were positively correlated with the decolorization． The preliminary technological parameters were: red light power 6 W，filling light 3 h /d and residence time five days． As this conditions，the chromaticity could be reduced from 40 times to 10 times and the removal rate would be reached to 75. 0%． In addition，artificial light could promote and accelerate the superoxide dismutase，catalase and peroxidase activity，which would enhance the resistance response of plants．