The researches on load forecasting of power system are of great significance to the electricity consumption analysis， electricity planning，rational arrangement of manpower and material resources，economical and effective management of power system． Firstly the background and current situation of electrical load research are analyzed，and the characteristics and procedures of electrical load forecasting and its common prediction methods are systematically summarized． And then from different point of view the characteristics of different prediction methods are analyzed and compared，moreover the electrical load forecasting in Sichuan province and the national electricity consumption situation are analyzed． Furthermore，the corresponding opinions and suggestions are put forward for the researches of electrical load forecasting．