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During the process of WEB development, the fixed database relational model often struggles to meet the changing needs of users in Database Application System (DAS). To achieve the dynamic structure of DB table, we present a user-adaptive relational model which adopts two static DB tables – master and slave. In this structure, the master table is used to store the user custom relational table information, while the slave to store all user-defined data. In the DAS which exploits this relational model, users can customize the data type and perform dynamic data management. Thus it, to some extent, realizes the adaptation of users’ changing needs. We illustrate the use of this model with the Data Sharing Platform in tobacco industry. The practical results show that the user adaptability to DAS and the performance of WEB sites have obvious improvement.