Abstract:Acoustic signal is important for bird communication. Differences in vocal characteristics are usually explained by habitat-dependent selection on signal transmission and/or sexual selection by female preference. The organ to produce signals can also be influence signal features. For example, the negative relationship between frequency and body size; negative relationship between frequency bandwidth and beak length. These negative relationships usually stand among species, but it is unclear if such relationships exist within species. We studied the sound from 17 individuals of Emberiza godlewskii, recorded in Beijing Xiaolongmen forest Park during the 2012 breeding season. We measured the maximum frequency, minimum frequency, peak frequency, frequency range, and found that none of these frequency traits was related to body size, or beak length. Possible reasons for these results are the vocal learning, female preferences, and small range of variation within species. Besides, we found peak frequency (6.31 kHz) is widely deviate from value (3.46 kHz) predicted for by empirical formula, which imply other selection than morphological measurement work on the vocal of Emberiza godlewskii.