In this paper, a prediction method for interlaminar fatigue life of carbon fiber-reinforced plastic (CFRP) is proposed based on an inelastic two-scale analysis method combined with the Coffin-Manson law. For this, the flatwise tension test of a CFRP is simulated using the two-scale analysis method, and the distributions of microscopic viscoplastic strain occurring at resin parts in micro-structures (unit cells) are examined. Then, the maximum value of microscopic viscoplastic strain is applied to the Coffin-Manson law for the resin to predict interlaminar fatigue life of the CFRP.