Based on quasi-static and dynamic experimental results, a novel strain-rate-dependent model for ethylene-propylene-diene monomer (EPDM) rubber was developed. This model, composed of a base model and rate-sensitivity terms, has a relatively simple form to be embedded in computer codes for numerical simulations. The base model combines a Maxwell model and a Mooney function. The Maxwell model is necessary to describe small-strain behavior, whereas the Mooney function dominates the large-strain behavior. Each of these two components is then multiplied by a rate-sensitive term to describe the material's strain-rate sensitivities at both small and large strains. This model gives a good description of EPDM response in both compression and tension over a wide range of strain rates with a minimum number of material constants. (C) 2004 Wiley Periodicals, Inc.