Photoinduced carrier dynamic behavior of the Mn 3+ 3d resonance excitation of YMnO 3 thin film is studied by the femtosecond time resolved spectroscopy. The photon energy of the pump pulse is tuned to 1.70 eV, which is corresponding to the Mn 3+ 3d energy level at room temperature. With resonant excitation, the transient transmission signals at the zero-delay time gradually increase with temperature increasing. The temperature dependent transmission change results from the blue shift of the Mn 3+ 3d energy level, which is believed to originate from the short-range antiferromagnetic order in YMnO 3 film. In addition, the fast and slow relaxations of the transient signal arise from electronic-phonon and phonon-spin interactions, respectively. When the temperature is lower than TN, the relaxation time of the fast process increases significantly, which indicates that the strength of electronic-phonon coupling is restrained by the long-range antiferromagnetic order. ©2012 Chinese Physical Society.