Composite materials have grown an increasing interest in the last decade. They present the advantage of reducing weight keeping an excellent weight to strength ratio. These materials found application in various fields such as aerospace, automobile etc. In the aeronautic field, replacing aluminum by carbon fiber based composite (CFC) allows a weight gain of 50 %. On the other hand, CFC has some inconvenience; the relatively high production cost and the process time that reaches few hours. Therefore, the in-situ monitoring of the physical properties, namely mechanical of such structure is of extreme importance. In this communication, we report the results of the monitoring of epoxy resin polymerization during the curing process. An experimental set-up was developed in order to measure in real time the evolution of elastic modulus. Depending on temperature, we could monitor the different phases of the polymerization process from the mechanical point of view. In fact we could observe a three-phase- polymerization process; softening of the material, hardening and finally stabilization of the mechanical properties. On the other hand, acoustic absorption was studied. This parameter exhibit an important change during the phase transition.