Nonspecific cytotoxic cell is the evolutionary precursor of mammalian natural killer cell in teleostean fishwhich was mainly separated from blood and lymphoid organ as the first barrier of defense to protect the animal against bacteriait plays an important role in nonspecific immunity and also has a function of killing tumor cells in vitro. In recent years the merged images from immunofluresence microscopy showed that NCAMP-1 and NCCRP-1 are coexpressed on NCC membranes and may participate in innate immunity against bacteria by granule exocytosis during inflammatory responses in teleosts.These membrane proteins are evolutively conserved from teleostean fish to mammalian. In this reviewand NCC receptor mechanism have been discussed in order to provide data for further research on NCC function in the innate immunity of fish.