In the paper, the method of optimization of 2-D trusses is discussed. The graph-based method was used for calculation of stresses in the truss bars. Some other papers where graphs are used for truss analysis are cited but usually rather different calculation engines were used. The evolutionary algorithm was utilized for optimization of trusses. The truss topology was assumed. The optimization task consists in changes of the coordinates of the nodes of the truss. An evolutionary approach is characteristic for a non-standard constructional solution (design) search which can be performed analyzing the whole population containing the solutions i.e. the optimal truss as well as other trusses enclosed in a population. There is a possibility that choosing a final truss some personal preferences of a designer can be taken into account. Some exemplary results of own computer program are enclosed.