Abstract: In order to tackle the bottleneck of heavy-workload and cumbersomeness with preliminary identification of high resolution electrospray mass spectrometric data, a software as Microsoft Excel Plug-in for batch automatic preliminary identification of high resolution electrospray mass spectrometric data was developed, which performs automatic identification and creates report of results based on information such as location of library data and data to be identified in an Excel document and mass accuracy, etc. designated by user. Test showed that the software produces same result compared with handwork, but saves manpower and greatly improves efficiency, with simple operation, high fault tolerance and practicability.