A new triazole-phenylamide derivative (DOT) is synthesized and its inhibiting action on the corrosion of mild steel in 1 mol/L HCl solution is investigated by means of potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. Thermodynamic and kinetic parameters are calculated and discussed. Then the surface morphology is studied by scanning electron microscopy (SEM). Results show that DOT strongly inhibits the corrosion of Q235. The inhibition efficiency of 0.001 mol·L-1 DOT is more than 96%. Polarization curves indicate that the DOT acts as a mixed-type inhibitor, the cathodic and anodic processes of corrosion are suppressed. Thermodynamic and kinetic parameters are obtained from weight loss of the different experimental temperatures, which suggests that at different temperatures (298~333 K) the adsorption of DOT on metal surface obey Langmuir adsorption isotherm model. The adsorption processes are exothermic reaction and belong to chemisorption and physisorption.