We have investigated the gas temperature during pulsed discharge. The gas temperature is one of the most important parameters for application of pulsed discharge in atmospheric gases. At atmospheric pressure gases, the gas temperature can be assumed equal to its rotational temperature. In the present work, the rotational temperature of the nitrogen molecules in a coaxial discharge reactor was obtained by synthesizing measured and calculated spectra. The emission spectrum was obtained from the second positive system of the nitrogen molecule due to the transition from the C(3)Pi(u) state to the B(3)Pi(g) state. As the result, rapidly increasing of the temperature (approximately 60 K) was observed at the boundary between the streamer and the glow-like discharge phases. In this paper, the spatial and the temporal dependences of the rotational temperature during pulsed discharge are reported. (C) 2011 The Japan Society of Applied Physics