Photoluminescence spectra at various temperatures of GaAs/AlGaAs asymmetric coupled double quantum wells pin structure are reported. Different temperature dependence of heavy-hole excitonic peaks intensity in narrow-and wide-well was observed.The results show that the thermionic emission of the electrons in the narrow-well results in more rapid decreasing of the luminescence intensity. The special temperature dependence of light-hole excitonic peaks intellsity in the wide-well and its mechanism were studied, too.