Glutinous rice exhibits the phenomenon of turning opaque during the drying process after harvest. This phenomenon is called "Haze." "Mihaze" grains are translucent even after artificial drying. To make clear the factors causing the appearance of Mihaze grains of glutinous rice in Hokkaido, moisture content of grains and cultivation conditions were investigated. As the moisture content of grains of glutinous rice was decreased by experimental drying, most of the grains turned opaque at a moisture content of less than 15.0%. However a few of them remained translucent at a moisture content below 15.0%, suggesting that there were Mihaze grains even at the low moisture content as commercial products. Therefore it was concluded that there are factors causing the appearance of Mihaze grains besides moisture content. The frequency of Mihaze grains was not affected directly by contents of protein and starch, and starch granule size. It was observed that there was no difference in contents of moisture, protein and starch, or starch granule size and iodine absorption spectrum of each prepared starch between Haze and Mihaze grains.