Based on the daily data from 90 meteorological stations in Shandong Province during 1961 to 2010,as well as use of the monthly potential evapotranspiration and monthly precipitation data,the relative moisture index was calculated. The extreme drought frequency in Shandong Province was analyzed meanwhile temporal and spatial variation characteristics of the extreme drought frequency in inter - annual,summer maize growth season and winter wheat growth season have been studied. The results showed that the average extreme drought frequency was 4.14n /a,and higher in northwest of Shandong and lower in southeast Shandong,eastern of the Peninsula. Climate change rate of the extreme drought frequency was - 0.069n /10a and decreased in northwest,southwest and south of Shandong. The extreme drought frequencies in winter wheat and summer maize growth season were0.45 n /a and 3.63n /a respectively,and its spatial distribution was obviously different; meanwhile the climate change rates were - 0.037 n /10a and - 0.049n /10a respectively. The extreme drought frequency of summer maize growth season was decreased in northwest Shandong and increased in southwest of middle Shandong Mountains,middle and west Peninsula. The extreme drought frequency of winter wheat growth season was decreased obviously around middle Shandong Mountains.