Abstract: A new theoretical method was presented to predict heavy ion single event upset （SEU) linear energy transfer threshold (LETth) from pulsed laser SEU simulation experimental results. In order to determine equivalent method validity, laboratory laser simulation system (LSS) was employed to measure the single event upset threshold for some electronic devices and integrated circuits. The experimental data of single event upset induced by pulsed laser were compared with the heavy ion SEU data. The results show that LETth of SEU induced by pulsed laser is consistent with the heavy ions for some devices and integrated circuits.