Abstract: The calculations of ionosphere propagation loss have important meaning for fundamental research of ionosphere and applications of HF communication or over-the-horizon radar, which are usually adopted by semi-empirical model. The parabolic equation methods for electromagnetic wave propagation are proposed to numerically calculate the space distribution of path loss affected by ionosphere at HF. The numerical techniques can consider effects of refraction, reflection, diffraction and absorption of ionospheric propagation simultaneously. Propagation loss is simulated under different frequency and beam width using a profile of electron concentration. The propagation mode, reflection height and situation are compared with the results from ray tracing, demonstrating that they are consistent with each other. Absorption effects for ionosphere are simulated and used to analyze by the numerical method. The study preliminarily shows the validity of the powerful numerical techniques of parabolic equation methods for assessing ionospheric propagation.