Abstract: The irradiation influence of electrostatic discharge electromagnetism pulse (ESD EMP) on circuit has been studied based on the theory of transmission line, and the mathematical model also been built. In order to measure the intensity of electric field around coupling planes, the ESD EMP radiation effect test has been done according to IEC61000-4-2. The experimental data indicates that the magnitude of induction voltage caused by horizontal coupling plane (HCP) is greater than the value caused by vertical coupling plane (VCP), especially as the circuit board of equipment under test (EUT) parallels the HCP, while the strength of radiation field is almost equal in the two modes. There is a good agreement between the mathematical model and the experimental result. Therefore, the model is right to study the ESD EMP coupling effect on electronic system. What's more, the study also has indicated that the IEC61000-4-2 standard has some flaws, the HCP will change the direction of electric field, which can cause greatly affects on the experimental data. So, the place of the EUT should be more unambiguous to reduce the uncertainty.