Abstract: Using the observation data of solar global radiation at 4 stations and sunshine percentages at 56 stations during 1961-2010 in the circum-Bohai Sea region, the spatial-temporal distribution and variations of solar global radiation in the recent 50 years were studied. In addition, evaluation of potential solar energy resource in the region was made by calculating the solar global radiation in the recent 20 years. The results showed that monthly solar global radiation showed a single peak pattern with the peak in May, and April to August being the period of abundant solar energy resource in a year. Solar global radiation generally shows a decreasing trend from 1961 to 2010. However, there was a clear turning point around 1990, with significant decrease before 1990 and no evident trend after 1990. For the whole circum-Bohai Sea region, there were large spatial differences in the interannual variation of solar global radiation. The largest decrease of solar global radiation from 1961 to 2010 occurred in Beijing, Tianjin, Tanggu and their surrounding areas as well as in the central and southern areas of Shandong Province, which may be related to the changes in aerosols as a result of industrial development. Interannual variations of solar global radiation in four seasons showed a similar significant decreasing trend, with higher decreasing rates in spring and summer compared with autumn and winter. Average solar global radiation during 1991-2010 was high in the northwest part of the region, decreasing gradually southwards and eastwards.