Abstract: The change in the diversity of China's primary energy supply was calculated and analyzed using the Shannon-Weiner index. The results showed that, from 1949 to 2005, the primary energy supply tended towards varied resources from the initial single one. In 1951, there were only 3 kinds of supplying resources and the minimum Shannon-Weiner index was 0.1545 with the minimum evenness 0.096, where the coal came up to 97% of the total supply and the rest including petroleum and hydropower was so poor that was just about 3%. In that period China's primary energy supply was at the lowest level. In 2001, the diversity of energy supplies came up to its peak, i.e., the maximum Shannon-Weiner index was 0.8669 with the maximum evenness 0.5387, including 5 kinds of supplying resources available. The differences between the percentages of those primary energy supplies became lowest in that year.