Software configuration management (SCM) systems are very important for coordinating group efforts in developing large and complex software systems. The ability to support concurrent software development is the key to deliver high quality software with low time-to-market, where merging is the core enabling technique. Textual merging is the primary and the only successful merging function available in today?s SCM systems. However, none of them supports complete textual merging, which is not only very useful itself but also the foundation for syntactic and semantic textual merging. In this paper, we propose a novel operation-based textual merging algorithm, which has the capability of supporting complete textual merging while still preserving the intentions of individual editing operations.