In distributed database, file replication and wordload balancing are ｉｍｐｏｒｔant design issues. This paper solves these two issues simultaneously. The primary objective is to optimize the system response time that consists of local processing and communication overhead on a local area network. The problem is presented in the form of a nonlinear integer programming model. The problem is proved to be NP-complete and thus a heuristic is developed. A numerical example is solved to illustrate the suitability of our design approach. The model and heuristic are likely to provide more effective distributed database designs.