The present paper djscribes a topological design of two-dimensional structure by cellular automaton. To solve the two-dimensional elastic problem, we use the finite element method. At the application of the cellular automaton, the element of the finite element method is regarded as cell. The cell can be in the two states, namely alive or dead. To generate or eliminate cells, we make a simple local rule based on the equivalent stress. Numerical simulation shows the various topologies of the structure in a prescribed design domain under the various local rules. Also, we discuss how the initial designs of the structure have affect to the final topology.