Abstract: Change in land use of the intertidal land resources of Dafeng City was analyzed with the aid of the remote-sensing technique and Landsat-TM data to evaluate service value of the intertidal land eco-system with the Costanza method.The results show that the service value has been on the decline due to irrational land use in the past 18 years.The loss was reckoned to be around 33.45%, or 88.37×10⁴ US in 2002.