Abstract: In order to improve the utilization efficiency of water resources of paddy field-wetland complex system in soda saline-alkali area and reduce the environmental impact of water retreat in irrigation area, according to the characteristics of water and soil resources in soda saline-alkali habitat, three kinds of aquatic plants were introduced and tested. Takes soda-alkali wetland as the research site, by introducing Oenanthe javanica, Ipomoea aquatica and Zizania caduciflora, growth indexes, photosynthetic physiological indexes and yield were observed under hydroponics and soil culture, and nitrogen and phosphorus absorption characteristics were studied. The results showed that the growth rate, photosynthetic rate, chlorophyll content, growth index and yield of Oenanthe javanica and Ipomoea aquatica were higher under water culture than those of soil culture, and the average yield per mu of Oenanthe javanica and Ipomoea aquatica was 1 148.11 kg and 863.76 kg higher under water culture than that of soil culture, respectively. The growth rate, photosynthetic rate, chlorophyll content, growth index and yield of Zizania caduciflora in soil culture were obviously higher than those in water culture, and the average yield per mu of Zizania caduciflora in soil culture was 1 043.34 kg higher than that in water culture. The total nitrogen content in the roots of the three aquatic plants was significantly higher under water culture than that of soil culture. The total nitrogen content in the roots of Oenanthe javanica, Ipomoea aquatica and Zizania latifolia was 136.26%, 106.82% and 24.51% higher under water culture than that in the soil culture, respectively. The total phosphorus content of the three aquatic plants under soil culture is obviously higher than that under hydroponics. Under soil culture, the total phosphorus content in the shoot and root of Oenanthe javanica is 28.57% and 33.33% higher than that under hydroponics, the total phosphorus content in the shoot of Ipomoea aquatica field is 77.78% higher than that under hydroponics, and the total phosphorus content in the shoot and root of Zizania caduciflora is 100.00% and 77.78% higher than that under hydroponics. The soluble sugar content of three aquatic plants in soil culture was significantly higher than that in water culture, and the soluble sugar content of Oenanthe javanica, Ipomoea aquatica and Zizania caduciflora was 50.98%, 43.21% and 22.90% higher than that in water culture, respectively.