Abstract: Unidirectional tensile tests of the auto-use electrolytic zinc IF steel plate were carried out at various temperatures and strain rates.Change of the stress-strain curves with the change of tensile temperature and strain rate was studied.Influences of tensile temperature and strain rate on the mechanical properties were discussed,and the variation of coefficient of strain rate sensitivity with the tensile temperature was analyzed.The results show that uniaxile tensile stress of the IF steel decreased with increasing the tensile temperature,while increased with increasing the tensile rate.Yield-strength ratio had an upward parabola tendency with increasing the temperature and its critical temperature was about 120 ℃.The hardening exponent showed different variation with the increasing temperature at different strain rates.Elongation at rupture changed little with the variation of the temperature and strain rate.And the critical temperature of the mechanical properties was between 100 and 120 ℃,while the maximum coefficient of the strain rate sensitivity was obtained at 60 ℃.Furthermore,the coefficient of the temperature sensitivity increased with increasing the strain rate.