Abstract: In order to reasonably select the site of sea drones,an entropy and TOPSIS based model is developed. The influencing factors are identified from three aspects,which are natural conditions,water conditions,and traffic con-ditions,and the airspace,waters and land conditions are comprehensively considered.Afterwards,the site selection index is derived,and a TOPSIS-based method is utilized.Information entropy is applied to determine weights of each influen-cing factors.The site of the sea drone is selected by using both information entropy and TOPSIS.The proposed model is applied to the site selection of seaplane in Zhenjiang.In this case four candidate sites of seaplanes are in this lower reaches of the Yangtze River,and the relative closeness degree of each alternative to the ideal point is 0.469/0.682/0.326/0. 295,respectively.Alternative 2 gets the maximum relative closeness degree,which is 0.682 and the best site among these four alternatives,and it is consistent with the actual selected site.The proposed entropy and TOPSIS based model uses objective information for judgments,which can reduce the errors caused by subjective assessment and also increase the credibility of decisions.