Performance optimizing of business database is a main problem encountered by system administrator, and it will impact the running of whole database system. This paper discusses foundation, principle and technique of SYBASE performance optimizing from the aspect of optimizing tool, database server, database structure design, database application and database running environment based on a truly application system. From the practice application point of view, it presents adoptive efficient optimizing technique and gives contrast before and after optimizing. Finally it explains that database performance optimizing is the precondition and basic to use the database efficiently.