The paper presents the results of an experimental study on fatigue performance of corroded reinforced concrete (RC) beams repaired with carbon fiber reinforced polymer (CFRP) sheets. Five beams were constructed. One specimen was strengthened and not corroded; another four specimens were corroded and was strengthened with CFRP sheets. Five specimens were tested in fatigue. The results showed that steel bars corrosion reduced the fatigue life significantly while the CFRP strengthening enhanced the fatigue performance significantly. The effects of reinforcement corrosion on fatigue behavior of the strengthening beam can be attributed to a combination of four factors, including deteriorated bond behavior between reinforcement bras and surrounding concrete, loss of effective cross-section area of reinforcement, the stress concentration on steel bars, and degradation of mechanical properties of steel bars.