Tailoring software process from existing software processes patterns and standards can effectively improve the performance of work process, ensure the quality of final products, avoid high risks, and reduce rework. However, existing researches do not propose a systematic method for tailoring software evolution process. We propose four basic blocks, namely sequence block, selection block, iteration block and concurrency block. Based on basic blocks, we define four software evolution process tailoring operations: adding operation, deleting operation, splitting operation and merging operation. Additionally, the interface between the high-level model and the low-level model is kept consistent when merging or splitting operation is carried out.