With powerful computer and mighty software, seasoned users could turn digital media into what they want. The detection of digital tampering has become a crucial problem. In most of the time, digital tampering is not perceptible by human: however, some traces of digital tampering may be left in the media during the process. Based on this idea, we present a method in this paper that could reveal blurred regions that indicate possible tampering without any embedded information such as watermarking technique. Effectiveness and results are presented, robustness is also discussed.