Abstract:The Yellow river delta area is near Bohai gulf. It has abundant mudflat wetland resources. The ecological environment in this area is very complex. In this paper, by using conceptual model of "ecological sensitivity——ecological pressure degree", ecological environmentl vulnerability evaluation index system has been set up. Through data standardization, the index unified dimension has been made, then according to the mathematical model, ecological environment vulnerability index have been calculated and divided into five grades. It is showed that ecological environment vulnerability level is high in northwest coast ,mainly distributed in northern dongying city which is concentrated wetland and salinization; the southern region is relatively low, especially the areas away from the coast. Finally the problems existing in the evaluation were discussed in this paper.