Abstract: Long time employment and frequent overload will result in structural damage and deterioration of bridges, therefore the overload and ultimate behavior of these bridges and their actual capacity are always important concerns of researchers worldwide. Although the actual bridge destruction tests are the most effective way to research in this field, the limitations of tests opportunities, cost and difficulties makes them seldom be carried out. This paper conducted a destruction test on a forty-three years old reinforced concrete simply supported T-beam bridge in Changsha City Hunan Province, when it was to be torn down for rebuilding. The experiment employed 8-12 hydraulic rams to simulate the over-load of the two-axle and three-axle trucks, to study the overload behavior of the bridge under simulated vehicle loads, and the damage accumulation resulting from the loading cycles was also analyzed. Furthermore, two 500t jacks were used to load the bridge till its destruction, and the mechanical performance of bridge during the whole process and the structure reaction in ultimate conditions were investigated. In this paper, some innovative work was made, which will contribute to the development of the design theory and the rating method of bridges.