Objective To investigate the characteristics of the tidal breathing pulmonary function in premature infants with different gestational ages. Methods A total of 75 premature infants were classified into three groups according to their gestational ages: <32 weeks, 32-33⁺⁶ weeks and 34-36⁺⁶ weeks. Fifty-five full-term infants (39-40 weeks group) were selected as the control group. All infants were given the tidal breathing pulmonary function test at 3-5 days after birth. Moreover, all infants were given the tidal breathing pulmonary function test again at 40 weeks of the corrected gestational age. Results At 3-5 days after birth, the three groups of premature infants had significantly lower inspiratory time, time to peak tidal expiratory flow (tPTEF), and ratio of tPTEF to total expiratory time (tPTEF/tE) than the control group (P<0.05). The parameter values of the tidal breathing pulmonary function were lower when the gestational age was lower. Even at 40 weeks of the corrected gestational age, the three groups of premature infants still had significantly lower tPTEF and tPTEF/tE than the control group (P<0.05). Conclusions The tidal breathing pulmonary function of neonates is influenced by the gestational age. The tidal breathing pulmonary function of premature infants is obviously impaired, and the lower the gestational age, the more obvious the impairment.