With the continuous acceleration of urbanization, noise levels in urban areas have significantly increased, which could mask the communication signals and thus pose a challenge to vocal communication of birds. Because the frequency of urban noise is generally low, birds could sing at high frequencies to avoid being masked in noisy urban environments. Lower frequency of vocalizations is an important indicator of male quality, however, the higher frequency of vocalizations would reduce the attractiveness of the vocalizations to females. Consequently, there is a trade-off for birds between raising and keeping vocalization frequency. With the aim to examine the effects of urban noise on vocalization of Tree Sparrows (Passer montanus), we compared the breeding songs of tree sparrows at six study sites in Shenyang with different noise levels from April to July 2019. We recorded the songs of Tree Sparrows at breeding stage using directional microphones and measured noise levels using a calibrated sound pressure level meter. Differences in song parameters and noise levels between urban and suburban sampling sites were analyzed by nested ANOVA. The Unary linear regression analysis was carried out on the mean of song parameters and the mean of noise for six study point tree sparrows, with noise level as an independent variable. Our results showed that the urban sites had higher noise levels than the suburban sites (P < 0.01, Table 2). Tree Sparrows in the urban sites had significantly higher maximum frequency (P < 0.01), higher minimum frequency (P < 0.05), higher peak frequency (P < 0.01), and wider bandwidth (P < 0.01) (Table 2). There was no significant difference of vocalization duration between tree sparrows in urban and suburban sites (P > 0.05, Table 2). The maximum frequency (P > 0.05), bandwidth (P > 0.05), peak frequency (P > 0.05), and duration (P > 0.05) were not significantly correlated with the noise (P > 0.05) (Fig. 3). The minimum frequency was positively correlated with the noise level (P < 0.01, Fig. 3). Our results indicated that, Tree Sparrows choose to increase the minimum frequency for better signal transmission in noisy environments.