‎There are different types of classification methods for classifying the certain data‎. ‎All the time the value of the variables is not certain and they may belong to the interval that is called uncertain data‎. ‎In recent years‎, ‎by assuming the distribution of the uncertain data is normal‎, ‎there are several estimation for the mean and variance of this distribution‎. ‎In this paper‎, ‎we consider the mean and variance for each of the start and end of intervals‎. ‎Thus we assume that the distribution of uncertain data is bivariate normal distribution‎. ‎We used the maximum likelihood to estimate the means and variances of the bivariate normal distribution‎. ‎Finally‎, ‎Based on the Naive Bayesian classification‎, ‎we propose a Bayesian mixture algorithm for classifying the certain and uncertain data‎. ‎The experimental results show that the proposed algorithm has high accuracy.