Semi-Fragile watermark has attracted attention due to its important role in content authentication for multimedia. In order to differentiate incidental attacks and malicious attacks, semi-fragile watermark must be robust against content-protection image processing. Semi-fragile watermark resisting to JPEG compression while maintaining high detection ability to tamper has been the emphasis in this area. In this paper, a semi-fragile watermarking algorithm to resist JPEG is proposed based on the fact that most of the coefficients of high frequency have the same relative energy relations after JPEG compression. The experimental results demonstrate that the proposed algorithm has the advantages such as simple computation complexity, big embedding capability, good robustness to JPEG, and exact location for tamper.