The energy absorption performance of extruded aluminum tube specimens for space frame was evaluated using computer-simulated compressive tests and quasi-static compressive deformation tests. Experimental deformation test and its simulation were conducted for seven extruded tube specimens on which various types of grooves were introduced, and the test data were investigated via observation of deformation mode, maximum resistant force, and absorbed energy. The results indicated that the computer simulation data correlated well with the compressive deformation behavior, indicating that the simulation was very useful for evaluation of the absorption energy performance. When the grooves were introduced at the folding sites pre-estimated by the computer simulation, the energy absorption performance could be improved, and the half-grooved specimens absorbed more effectively than the full-grooved specimens. On the other hand, when the grooves of the same interval were introduced without consideration of the folding sites, unhomogeneous deformation, together with bending, occurred, and deteriorated the energy absorption performance because energies were not as effectively absorbed as on folding.