In this paper,the principle and the method for the measurement of Poisson ratio of C/ C composite
material by laser holographic interterometry are described. The result shows that this method is especially suitable for
the measurement of C/ C composite Poisson’ s ratio. The mean value of Poisson’ s ratio of braided C/ C, needled
punching C/ C, felted C/ C were 0. 196, 0. 183, 0. 040.