Indexes of sulfide ores in oxidation process at ambient temperature are the main indicators in the identification of the spontaneous combustion tendency. The method of comprehensive analysis of multiple factors is widely used in evaluating the oxidizing strength of sulfide ores. However, this method needs lots of evalution indexes and the process of determination is complicated and difficult.The multiple indexes need to be simplified. Correlation analysis is a way to solve this problem. In this paper, taking the sulfide ores of Dongguashan Copper as an example, the software SPSS is used to analyze the correlation of different indexes, including those of the weight gain, the rate of oxygen, the contents of SO₄^2-, the contents of Fe²⁺+Fe³⁺ and the pH value, with theoretical interpretations. Based on this study, the main and important indexes can be chosen, to simplify indexes and to optimize the indexes in the identification of the spontaneous combustion tendency.