Abstract: The present paper deals with improving automatically SQL Server queries in order to increase database performance. This article aims to provide the proposal algorithm called AIQ (Algorithm Improvement of Query) based on program language C# in order to improve automatically the ten queries compiled from various published articles by researchers and also compare the performance of algorithm AIQ with that of SQL Server query optimizer. To achieve these purposes, the mixed method (descriptive and experimental) research design is conducted and then proposal algorithm is provided by researcher and finally query execute time in algorithm AIQ in mode of inactive SQL Server query optimizer is compared with that of in SQL Server in mode of active SQL Server query optimizer on database of Insurance Company. The result obtained shows that speed of improving query with use of proposed algorithm AIQ is more than that of SQL Server query optimizer.