A new method is proposed to extract the trap states in p-channel SnO thin-film transistors (TFTs). In this method, the dominant conduction mechanisms under different temperatures have been taken into account. There are percolation and multiple trapping conduction mechanisms. Combined with the drain current-temperature (I-ds-T) and capacitance-voltage (C-V) measurements, the variation of trap states concentrations with the surface potential is derived. Results show that energy-dependent density of states (DOS) is in the order of 10(19) eV/cm(3). And the maximum of the density of states at the interface between the gate dielectric and the SnO channel is N-ss = 1.77 x 10(14) cm(-2) eV(-1). (C) 2016 Elsevier Ltd. All rights reserved.