Seawater desalination is an important way to alleviate the shortage of water resources in the coastal area. To provide reference for investment decisions on seawater desalination, this paper made the economic effects analysis of seawater desalination investment in China. The competitive partial closed input-output model was applied. The results showed that the seawater desalination sector had a large investment multiplier 2.49 (ranked 9th in 18 sectors). Its influence coefficient and sensitivity coefficient were 1.09 (ranked 8th) and 1.14 (ranked 6th) separately, which revealed that it had obvious demand pulling and supply pushing effects on the national economy. Crown Copyright (C) 2015 Published by Elsevier B.V. All rights reserved.