The objective of this study is to investigate failure mechanisms of compression fatigue behavior of impact-damaged CFRP laminates. Two kinds of composite materials, UT500/Epoxy and AS4/PEEK, were used to examine the dependence of failure behavior on the material properties such as interlaminar toughness. Impact-induced delaminations in the UT500/Epoxy specimen were relatively larger than those in the AS4/PEEK specimen. The S-N curves for the UT500/Epoxy specimens with impact damage showed a similar tendency to those without impact. And the impactinduced delamination in the UT500/Epoxy specimen grew widthwise to the free edge on the rear side of the specimen during the fatigue test. On the other hand, the AS4/PEEK specimens without impact showed the steeper slope of the S-N curve in comparison with those with impact. The delaminations in the impacted AS4/PEEK specimen never reached the free edge before the fatigue fracture.