This paper presents a method to simulate impedance characteristic of symmetrical dipole with MATLAB. At the same time, a program of simulating impedance of symmetrical dipole is given. Then for complicated sine integral and prolix formulae, the study on symmetrical dipole can be easily solved by MATLAB. The simulation results show that half wave dipole and full wave dipole are all predominant, besides half wave dipole has a better directivity coefficient. From the view of simulation, the results gained here will benefit to the simulation of input impedance and error description of other antennas.