Migration is the most often used preservation approach in long-term preservation systems. To design a migration plan, custodians need to know about technical infrastructure about a preservation system, characteristics and provenance about digital materials, restrictions about preservation activities, and policies about retention rules. However, current tools cannot provide all these information. They just can output information about formats and characteristics for several given formats. Hence, in this paper, we design a migration metadata extraction tool. This tool uses the stored metadata to retrieve the above information for the custodians. The test results show that due to the limitation on the stored metadata, our solution still cannot get the sufficient information. However, it outputs more migration metadata and has better performance than current tools.