Abstract: This research aims at indicating the influence rule of hydrophyte silt on the nitrogen and phosphorus transformation in soil treatment and restoration systems. Then provide basis for the harvestry in the operation and management of these systems. The soak test was made for Eremochloa ophiuroides, Potamogeton crispus L and Ceratophyllum demersum selecting from common submerged plant that planted in barrel indoor. The contaminants release rule induced by dissolution of plant’s tissue was inspected. The result shows that the quickest release happened within the first 8 hours. The release amount of total nitrogen was less than that of phosphorus. Eremochloa ophiuroides had the highest release amount of total nitrogen, which is 0.164mg/g, and then is Ceratophyllum demersum (0.081mg/g), the least is Potamogeton crispus L (0.064mg/g). Ceratophyllum demersum had the highest release amount of total phosphorus, which is (3.043mg/g), and then is Potamogeton crispus L (2.404mg/g), the least is Eremochloa ophiuroides (1.906mg/g). For the following three kinds of submerged hydropgytes, Eremochloa ophiuroides, Potamogeton crispus L and Ceratophyllum demersum, the phosphorus release amounts per g hydrophytes were high, thus the harvest should be carried out to avoid the phosphorus content in water increased caused by the release from hydrophyte during the decay period. The soak test was made for Myriophyllum spicatum-a common submerged plant that planted indoor. Four temperatures were settled as 5℃, 15℃, 25℃, 35℃, to inspect. The effect of temperature on the contaminants release induced by dissolution of plant’s tissue was studied. The results showed that the quickest release happened within the first 8 hours. The highest release amount happened when the water temperature was 25℃ condition, if the other conditions were the same, only the temperature value changed.