This paper presents some results from a comprehensive experimental program designed to determine the interaction between mechanical loading and corrosion of reinforcing steel, as well as their combined effect on serviceability and residual load- bearing capacity of reinforced concrete beams. Beam specimens with the size of 120mm×200mm×1700mm were subjected to four-point bending at various sustained loading levels (0%, 25%, 45%, and 65% of the ultimate load) during the corrosion test process. The marine tidal zone was simulated by alternating spraying and draining of 3.5% NaCl solution. An external direct current technique was used to accelerate the corrosion of the reinforcement. Residual flexural load-bearing capacity of the beams was evaluated at the end of the experiment. The results indicate that the loading has a significant effect on corrosion. Under simultaneous loading and accelerated corrosion conditions, the time-dependent deflection of the beams increases with the progressive corrosion of the reinforcement. The beams under high-level loading deteriorate more rapidly than those under low-level loading and without loading. As a result, the residual flexural capacity of the beams subjected to higher level loading was much lower than that of the beams subjected to lower level loading and in the absence of loading. The results suggest that, for a rational service-life prediction of reinforced concrete structures, the influence of the service load on the structural performance should be considered in combination with environmental conditions. This paper presents some results from a comprehensive experimental program designed to determine the interaction between mechanical loading and corrosion of reinforcing steel, as well as their combined effect on serviceability and residual load- bearing capacity of reinforced concrete beams. Beam specimens with the size of 120mm × 200mm × 1700mm were subjected to four-point bending at various sustained loading levels (0%, 25%, 45%, and 65% of the ultimate load) during the corrosion test process. The marine tidal zone was simulated by alternating spraying and draining of 3.5% NaCl solution. An external direct current technique was used to accelerate the corrosion of the reinforcement. Residual flexural load-bearing capacity of the beams was evaluated at the end of the experiment. The results indicate that the loading has a significant effect on corrosion. Under simultaneous loading of accelerated increases in corrosion conditions, the time-dependent deflection of the beams increases with the progress ive corrosion of the reinforcement. The beams under high-level loading deteriorate more rapidly than those under low-level loading and without loading. As a result, the residual flexural capacity of the beams subjected to higher level loading was much lower than that of the beams of to lower level loading and in the absence of loading. The results suggest that, for a rational service-life prediction of reinforced concrete structures, the influence of the service load on the structural performance should be considered in combination with environmental conditions.