Аннотация:The photophysical mechanism of laser ablation related to the change in activation energy for desorption (or destruction and further elimination) of electronically excited molecules is discussed. Despite the obvious physical reasons, up to now there is no experimental confirmation that this mechanism plays an important role with nanosecond laser ablation where duration of the laser pulse is longer than the corresponding relaxation time (typically, tens of picoseconds). On the other hand there was no special study of this mechanism for Ultra Short Laser Pulses (USLP) with pulse duration significantly shorter than the electronic energy relaxation time. Here we present the theoretical investigation of the photophysical ablation features with USLP and compare predictions which follow for the photophysical and pure thermal models.