This paper presents a waveform selection criterion for the purpose of low probability of interception (LPI). As various signal processing methods can be employed by channelized receivers, here we use the obtained amount of information from a specific transmitted waveform in interceptors to describe the LPI performance of the transmitted waveform. In this paper, the Shannon entropies of the received noisy waveform and background noise of interceptors are calculated respectively based on the distributions of power spectrum. The difference between the two entropies is the information content the interceptors can achieve to detect, recognize and classify the received waveform. And the relative difference can be treated as the waveform selection metric. A lower value of relative difference means a better LPI performance against channelized receivers. Simulation results show the proposed waveform selection method is correct and effective.