Wet granules are utilized in various fields due to their high workability and cost performance. However, it is difficult to observe the water distribution of wet granules directly because such granules only contain extremely small amounts of water. In this study, the water distribution of wet granules was investigated using a confocal laser microscope and quantitatively analyzed using an autocorrelation function. Furthermore, the correlation length of wet granules estimated from the autocorrelation function was compared with the shear properties of the granules. Consequently, it was found that the internal friction angle of wet granules decreased as the water volume between particles increased. These results indicated that the water in wet granules works as a drag reduction agent under shear conditions. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).