Abstract: A hybrid algorithm (HA) integrating the quasi-full stress algorithm and the standard genetic algorithm (SGA) is proposed to expedite the evolving process of genetic algorithm so as to apply it to the topology optimization of truss structures with discrete variables. Based on a force analysis of truss structures, a necessary modification is done in a heuristic way to the topological structure types that form randomly, thus forming rapidly such types to meet the requirement of their adaptabilities. The genetic algorithm is used to optimize the topology of truss structures and the quasi-full stress algorithm used to optimize cross-sections, then the results of cross-section optimization are transferred to genetic algorithm as the basis of genetic operation in topology optimization. The solution space to be optimized simply by genetic algorithm can thus be reduced greatly so as to expedite search process. The exemplification results show that the method proposed is really simple, fast and efficient to the topology optimization of structures.