Conceptual design method for the upper beam of the press is proposed. Based on the technical parameters (nominal load and tablesize) and press structural scheme (number and layout of the hydraulic cylinder), simplified mechanical model of upper beam is established and then the conceptual design model is derived. According to the model, conceptual prototype with equivalent moment of inertia of the cross section is achieved. The structure prototype of upper beam is then obtained based on the conceptual prototype by introducing the design rules and experience and solving an optimization model. The method is applied to the structure prototype design of upper beam of a 100MN hydraulic press.