Abstract: An experiment on constructing Alnus trabeculosa forest in wetland with different underground water level was carried out in Sha County of Fujian, the results showed that Alnus trabeculosa can be established in the wetland, furthermore the stand growth was better when the underground water level was low (40-60 cm) with survival rate of 94.4% and afforestation preservation rate of 93.8%, the average DBH of 10 years-old plant was 10.8 cm, the average height was 10.8 m, standing timber volume was 148.5681 m³/hm², the average biomass was 17.97 kg/plant, and the tree layer biomass was 52.005 t/hm².