Abstract: Orthogonal frequency division multiplexing(OFDM)is an attractive technology for wireless communication. Considering the vulnerability of being jammed for wireless system, the OFDM performance under multi-tone jamming and multipath fading was investigated. Firstly, the system model was described. Then, the received signals, affected by multi-path fading and jamming, were investigated theoretically. The statistical of the useful part and the interference of received signal was analyzed and finally, the bit error rate (BER) was achieved. Simulation results show that theoretical results agree well with the simulated ones. The jamming effect can be alleviated by increasing the subcarrier spacing. Expected results also show that the all-tone jamming is effective for big jamming power signal while the partial-tone jamming is better for small jamming power signal.