Abstract: In this paper, we give confidence intervals for mean life θ based on grouped data and binary data under exponential distribution. The approximated confidence interval is \left(\frac2 r \hat\theta\chi_\frac\alpha2^2(2 r+2), \quad \frac2 r \hat\theta\chi_1-\frac\alpha2^2(2 r)\right),where \hat\theta is MLE,r is the failure number.