The electromagnetic (EM) characteristics of log-periodic antenna (LPDA) are studied by adopting high order Method of Moment (MoM). Firstly, the antenna is segmented via generalized wire geometrical modeling. Then, electric field integral equations are formed based on EM boundary conditions. Finally, by virtue of high order MoM in which mixed-domain basis functions are adopted, the equations are made discrete and solved. The results of simulation show that this method is simple, accurate and has some practical value and theoretical meanings