The ChiMerg algorithm and its extensions have been shown to be efficient and effective for discretization of continuous attributes. However, all these algorithms have a vital drawback, i.e., the sense of probability is not fully carried out in two merged intervals. To overcome this drawback, this paper proposes the Integral Chi2 Algorithm based on the Chi2 algorithm. In the proposed algorithm, the meanings of probability and statistics are associated with criterion of interval merging. Extensive experiments are conducted to evaluate the performance of the proposed algorithm by comparing with existing algorithms. The experimental results show that our algorithm outperforms existing algorithms in overall.