Three types of granules, eosinophilic granule (αG), chromophobic granule (βG) and basophilic granule (γG) were observed in the cytoplasm of a single neutrophil from devil stinger Inimicus japonicus. The αG was round or oval and stained orange with Giemsa, but not with May-Grünwald (MG) and MG-Giemsa (MGG). On the other hand, the γG was stained light blue with not only Giemsa but also MG and MGG. Alkaline phosphatase was detected in the neutrophil as granular positive, but, acid phosphatase, β-glucronidase and some esterases were negative. Peroxidase activity was observed in the βG.