Coastal polynya plays an important role for the climate system because of the dense shelf water (DSW) formation. In the Sea of Okhotsk, the DSW is thought to be main source for ventilation of the North Pacific intermediate water (NPIW). However, in the polynya region, in situ observation is quite difficult due to severe weather conditions and thus the basic knowledge of the polynya is limited. In this study, characteristics of ice in the Okhotsk coastal polynyas are examined from comparisons among satellite and in situ observed data. The satellite data used in this study are from the Aqua/AMSR-E and the QuikSCAT/SeaWinds. The AMSR-E data are used to estimate thin-ice thickness. Backscatter from the QuikSCAT is used to detect ice types. For the validation, ice draft measured by ice-profiling sonar in the coastal region of northeastern Sakhalin for the period of December 2002 to June 2003 and daily picture of the coastal polynya taken from the coast near Magadan, Russia, for the period of December 2006 to April 2007 are used. In the coastal polynyas, most of the ice thicknesses from the AMSR-E are ＜0.1 m. The thin-ice regions correspond well with the low backscatter (<–18 dB) regions. Thin ice can be roughly classified into three ice types: grease ice, nilas and pancake ice. The backscatter of grease ice and nilas is considered to be lower than the other ice types, including thick ice, because the ice surface is quite smooth like mirrors. A feature of pancake ice is elevated rim with a nearly uniform height of several centimeters. The rim is formed by collisions between ice floes due to oceanic swells and is considered to act as major roughness elements without directivity. Thus, the result that the thin-ice regions correspond well with the low backscatter regions suggests that the coastal polynya is covered with grease ice and/or nilas. Occasional cases that the backscatter in the coastal polynya is high are possibly caused by pancake ice because these cases are shown simultaneously with stormy conditions resulting from the approach of a low-pressure system. At the edge of the coastal polynya, the backscatter is relatively high. This indicates that the ice surface is rougher than that in the coastal polynya and that ice motion is convergent in this area. The results from satellite observations are supported by in situ observations.