In this study, research on the dynamic behavior of inflatable dams will be undertaken. Such dams are used in the United States, Australia, and other countries for water impoundment, flood control, diversion of flow, raising spillway elevations, and other purposes. They also have potential application as a transportable flood control device. Even though a few of these dams have failed dynamically, published analyses have only considered static forces and deflections. The vibrations and dynamic response of inflatable dams will be studied systematically. The dams may be inflated by air, water, or a combination of air and water. The dam material acts like a membrane and cannot sustain bending or compression. The effects of various assumptions related to the fluid and membrane properties, such as incompressibility and inextensibility, will be investigated. Particular attention will be focused on conditions for local or global instability of the dam.