Abstract: A simple step-stress accelerated life test （ALT） is a step-stress ALT with only two higher stresses. The present paper considers simple failure-step-stress ALT for censored data assumed to be from an exponential distribution. The point estimators and confidence limits of some reliability characters under usual stress are given. An optimum simple failure-step-stress plan is suggested. The optimization is based on minimizing a close approximation to the exaot variance of log mean time at the usual stress. Finally, an example is used to illustrate our techniques.