Abstract: To investigate the mechanical performances of the concrete beams externally bonded fiber reinforced polymer （FRP) under severe environmental conditions, seven shear-strengthened beams with CFRP were designed and studies in the artificial accelerating test of sulfate solution dry-wet cycling degradation. Experimental results show that sulfate solution dry-wet cycling degradation affects significantly the shear behavior of shear-strengthened beams. The shear capacity of specimen decreases obviously with the time of the artificial ageing test and the FRP effective strain reduces rapidly. However, the strain distribution of FRP along the beam's longitudinal axis seems not to be influenced by the sulfate/dry-wet cycling corrosion.