A new method of integral estimate for interval censored data is presented in this paper.The integral distribution parameter estimators and their covariance are derived

the confidence limits of percentiles and percentages for the interval censored data from normal distribution

Weibull distribution or other location-scale distribution are also obtained.This method takes test data in different states as an integer

makes an statistical inference

and extends traditional regression analysis that is only suitable for complete data to interval censored data.