This article presents a program named SPICE for simulation in plant physiology. It was originally developed to simulate electric and electronic circuits. For several years it has now been also used in various fields of human and animal physiology (classical physiology, membrane biophysics, pharmacokinetics...). After a short description of SPICE’s main features and capabilities, 3 simple illustrative examples are given : a whole plant water flow model, a coupling fluxes of water and solute across a membrane and a process obeying the Michaelis-Menten law. The advantage of this approach is that the modeler need know nothing of numerical analysis and can nonetheless treat complex, non linear-systems. Cheap versions for IBM-compatible personal computers are available.