Morphological and cytochemical characteristics of neutrophil in Japanese lates, Lates japonicus were examined by light microscopy. The shape of neutrophils was round to oval (8.0-12.0 μm in diameter) and the nucleus round to lobule-shaped. Granules of the neutrophil were classified into two types, chromophobic granule (βG) and basophilic granule (γG). The βG was round to oval (≦0.5 μm in diameter), unstained by Romanowsky type stain (May-Grünwald (MG), Giemsa and MG-Giemsa) and peroxidase positive. The γG was round to oval (≦0.3 μm in diameter) and stained light blue with Romanovsky type stain under various conditions. This granule was alkaline phosphatase and toluidine blue (TB) positive. The Yasumoto body was also found in the neutrophil and TB positive.