The mechanical characterization of composite materials is a research axis of scientific and economic importance. In fact, it is essential to measure the elastic constants of a material with accuracy in order to realize structural analysis and to optimize the design. Among the developed methods, the static methods based on strain measurement present some disadvantages: destructive evaluation and difficulties of measuring the out-of-plane elastic modulus because of the thinness. These disadvantages could be avoided by the use of non-destructive dynamic methods such as modal analysis or ultrasonic waves evaluation. Among the non-destructive methods, ultrasounds are efficient. Besides, because of the accuracy of the results as well as the repeatability of the measures, scientists are generalizing this method. This paper presents a way to determine the mechanical properties of carbon fiber composite materials. This work underlines the results obtained of phase velocity at different incident angles with a dynamic characterization method which is developed as part of non-destructive evaluation by ultrasonic waves.