The corrosion behavior of mild steel in 1.0 M HCl was carried out at 25.00C, 35.00C and 45.00C using various concentrations of hexylamine as corrosion inhibitor by weight loss technique and other different techniques i.e. potentiodynamic polarization, Electrochemical impedance spectroscopy (EIS) at 25.00C. Trinocular metallurgical research microscope was used for surface study. From the weight loss measurement the maximum percentage corrosion inhibition efficiency 65.66% was observed for 800ppm concentration of hexylamine at 25.00C. By electrochemical impedance study it observed that charge transfer resistance (Rct) value increases and double layer capacitance (Cdl) value decreases with increasing the hexylamine concentration hence inhibition efficiency increases. By potentiodynamic polarization study it was observed that hexylamine behave as mixed type corrosion inhibitor. From the surface study it can be seen that on increasing the inhibitor concentration there is formation of protective layer on the surface of mild steel to protect the surface against corrosion and surface become smooth and more clean & clear. By all above techniques study shows that hexylamine is a good corrosion inhibitor for mild steel in 1.0 M HCl.