The degradation phenomena of DH lasers operating at room-temperature have been observed. It is found that some lasers degrade in a short time and their differential quantum efficiencies decrease while the threshold currents increase. It has been demonstrated in aging test at elevated temperature that the life-time can exceed ten thousand hours if the thermal stability of a laser is good and the increase rate of its threshold current (△Jth/Jth 103 hours)within a longer peried(over 250 hours)is less than 3%.