Carriers mobility model of olygomer and polymer semiconductor based OFET (Organic Field Effect Transistor) structures is presented in this paper. Starting from the conduction mechanism in the mentioned organic materials, a carrier mobility dependence on temperature, electric field and trap density μ(T,E,NT) was investigated, inspiring directly the current-voltage I(V) model of OFET structures. Subsequent simulations were also performed and the obtained results compared with the data available in the literature.