Deep Level Transient Spectroscopy (DLTS) technique has been used for measurement of the samples containing InAs/GaAs self-assembled Quantum Dots (QDs).The thermal activated energies of carrier emissions have been determined for the relevant levels.It has been found that Multi-Phonon Emission (MPE) is accompanied with the electron capture process of the QD level

there exists broadenning in the QD levels

and there is metastable growth configuration under some special conditions.The results show that DLTS has its peculiar functions in the study of QD systems.