Camellia is one of the widely used block ciphers, which has been selected as an international standard by ISO/IEC. This paper introduces a 7-round impossible differential of Camellia including
layer. Utilizing impossible differential attack, 10-round Camellia-128 is breakable with 2
chosen plaintexts and 2
10 round encryptions. Moreover, 10-round Camellia-192 and 11-round Camellia-256 can also be analyzed, the time complexity are about 2
, respectively. Comparing with known attacks on reduced round Camellia including
layer, our results are better than all of them.