In this paper, we have investigated the trapping phenomenon in AlInN/ GaN HEMTs using the drain current transient spectroscopy. From the trapping and detrapping drain current transient analysis under different biasing conditions, energy levels and locations of associated traps are extracted. Surface traps with activation energy of ~0.18 eV and buffer traps of energy ~0.27 eV were identified from this analysis. Hopping conduction of trapped surface electrons are also identified from this study. © Springer Nature Switzerland AG 2019.