An adaptive identification method was proposed to estimate for the characteristics of high power amplifiers (HPA) with memory in orthogonal frequency division multiplexing (OFDM) communication systems. The complex Wiener-Hammerstein model (WHM) was adopted to describe the input-output relationship of unknown HPA and a power series model with memory (PSMWM) was used to approximate the HPA expressed by WHM in base-band. Furthermore，the orders of PSMWM were chosen by Akaikes information criterion (AIC), and the RLS algorithm was used to estimate parameters of HPA in on-line manner. Finally，the effectiveness and fast convergence of the proposed identification method are validated by numerical simulation example.