This study verified that it is possible to classify water resource climate by precipitation using available water resource index (AWRI). To investigate water climate quantitatively, water resource climate index (WRCI) has been made, which could be identified regional distribution of water resource at a glance. Using WRCI, water resource climate of South Korea and global region was diagnosed. WRCI is consisted of annual precipitation average and statistics of AWRI during 1981-2010. AWRI is the accumulated precipitation value in which daily reduction of water, and the duration of accumulation are taken into account quantitatively. Before analysis, differences between precipitation and water resource index are investigated through principal component analysis using rotated-empirical orthogonal function and periodicity analysis using Fourier Transform. Because water resource index has a certain value although daily precipitation is zero, it is possible to analyze the characteristics of water climate not to be investigated by disorder of precipitation occurrence and intensity. Applying WRCI at South Korea, the most abundant region with annual precipitation average (1,930mm) and daily AWRI average (299mm) is Sungsan station of Jeju Island however, Daegwallyeong station has the largest difference of AWRI variability (617mm). In global region, equator region has an abundant water resource however, the difference of water resource variability is the highest in area of 10~20°N of northern hemisphere and 10~20°S of southern hemisphere. South Korea and southern region of Japan were verified to have a large difference of water resource variability, although they are located in middle latitude of northern hemisphere. We expect that distribution of each component in WRCI is available for classifying the areas with high occurrence possibility of flood or drought and establishing the new criteria of vegetation globally.