Abstract: In this paper we give approximate unbiased estimates （AUE） of sacle parameter σ and location parameter μ of extreme value distribution on type I censoring. Next, we study statistical analysis of accelerated constant-stress life test（ACSLT）for Weibull distribution on type I censor- ing and give AUE of the coefficients in acceleration equation and estimates of various reliability characteristics under the usual stress. Finally, a numerical example in given to show that our method is simple in computation and usable in application.