Objective To investigate whether sodium tanshinone ⅡA sulphonate ( STS) treatment attenuates pulmonary edema of seawater drowning ( PE-SWD) , and examine the effects of STS on Na-KATPase(NKA) in PE-SWD. Methods Thirty-six rats were randomly divided into there groups, ie. a normal group ( NG) , a seawater group ( SG) , and a STS treatment group ( TG) . The rat model of PE-SWD was established by seawater instillation. PaO2 , histological changes of lungs, lung wet /dry weight ratio ( W/D) ,pulmonary microvascular permeability ( PMVP) , and NKA activity were detected. Western blot were used to test the effects of STS on NKA-α1 expression. Results Seawater instillation decreased PaO2 and the expression of NKA, while increased W/D ratio and PMVP. At 2 h after seawater instillation, the PaO2 in the TG group were significantly higher than those in the SG group, and peaked at 4 h after seawater instillation.Histological examination showed that there were hemorrhage, edema, markedly thickened alveolar wall, and infiltration of inflammatory cells in alveolar spaces in the SG group, but lung injury was significantly alleviated in the TG group. W/D ratio and PMVP in the TG group were significantly lower than those in the SG group. Additionally, NKA activity and NKA-α1 expression were significantly higher in the TG group than those in the SG group. Conclusion STS treatment can attenuate pulmonary edema of seawater drowning which may be related with up-regulating Na-K-ATPase activity and expression.