In this paper, the high-throughput 12-mode convolutional turbo decoder which employs the parallel-window enhanced Max-log-MAP decoding is presented for WiMAX standard. To satisfy the multiple transmissions, 10 parallel windows decoding and the basic parallel-window designs are realized to have the features of efficient reconfigurability and no memory collision. After the implementation using the TSMC 0.13 mum CMOS process, the proposed WiMAX-compliant 12-mode CTC decoder occupies silicon area of 5.21 mm2 and achieves the maximum throughput rate of 115.4 Mbps.