The control of mold surface temperature is an important factor that affects sample surface morphology, frozen orientation and cooling stresses close to the skin, surface finishing, weld lines finishing and strength. The frozen layer thickness formed during the filling stage also has a very significant effect on the flow resistance and thus on the resulting pressure drop and flow length in thin wall parts. The possibility to have a hot mold during filling and a quick cooling soon afterward is precious for micro injection molding and for the reproduction of micro structured surfaces. Up to now, several methods (electromagnetic, infrared, hot vapor fleshing etc,) were tried to achieve fast temperature evolution. However, all these methods require a complex balance between thermal and mechanical problems, equipment cost, energy consumption, molding cycle time and part quality achievable. In this work, a thin electrical resistance was designed and used to generate a fast temperature increase on mold surface (by joule effect), followed by a fast temperature decrease after the electrical resistance deactivation. Since the whole temperature evolution can take place in few seconds, one can couple the advantages of a high surface temperature during filling with the advantages of a low mold temperature, fast cooling and low heating dissipation. Some experiments were performed with a commercial iPP resin, the effects of the surface temperature at the first contact with the melt and of the heating time (under constant power) on surface finishing and on the final morphology (thickness and structure of the different layers) are explored and discussed. Acknowledgment: This work has been carried out with the support of the POR CAMPANIA Rete di Eccellenza FSE. Progetto "MAteriali e STrutture Intelligenti", MASTRI Keywords: iPP, Injection moulding, Mold surface temperature evolution