Gliding bacteria M₁₆₅ was isolated from roted gill of grass carp(Ctenopharvngodon idellus). It is capable of infections and even causing death to thefish as well as to other pond fishes through multi-infections in water. The biologicalcharacteristics of M₁₅₅ resembles Myxococcus piscisola, but it could not quickly producemicrospore by Dworkin's method. DNA (G+C) of the bacteria is 35.3%. Quite dif-ferent from Myxococcus, it should belong to Flexibacter columnaris.