This study conducts experimental investigation and numerical analysis for one-stage thermoelectric cooler (TEC) considering Thomson effect. Three Seebeck coefficient models are applied to numerically and experimentally study the Thomson effect on TEC. Results show that higher current, higher hot side temperature, or lower heat load can increase the temperature difference between the cold and hot sides. Opposite trends are found for COP. Specific current should be chosen as the upper threshold in thermoelectric cooler design. The cooling performance can improve when the Thomson heat maintains positive. (C) 2011 Elsevier Ltd. All rights reserved.