In order to evaluate the capability that block ciphers resist differential attack accurately
a multiple differential cryptanalysis method is proposed in which chi-square statistics is constructed based on multiple differential characteristics with high probablities.We analyze the probability distribution of statistics corresponding correct key and incorrect key
and give the relation of data complexity
computational complexity and success probability.We point that the multiple differential cryptanalysis method can be applied to the the instance when the probabilities of differential characteristics are unknown.