The amplitude of magnetic permeability and the electromagnetic losses of silicon steel sheet are important to design all kinds of motors. It is necessary to analyze magnetic permeability and electromagnetic losses before designing efficient motors. Different magnetic hysteresis loops are measured using AMH-1M-S dynamic testing system from Laboratorio Elettrofisico Walker LDJ Scientific, Italy under different conditions, which are the same saturated magnetic field under different frequencies, the same magnetic field frequency under different maximum saturation flux density and the same maximum saturation flux density under different frequencies. The amplitude of magnetic permeability, medium energy storage and magnetic losses are analyzed using the testing data. The results show that amplitude of magnetic permeability decreases continuously and electromagnetic loss increases rapidly with the increasing of frequency under the same saturation magnetic field. Amplitude of magnetic permeability increases continuously. Energy storage medium and electromagnetic loss increase respectively with the increasing of maximum saturation flux density under the same frequency. Amplitude of magnetic permeability reduces continuously and electromagnetic loss increases rapidly with the increasing of magnetic field frequency under the same maximum saturation flux density. The detailed results from magnetic hysteresis curves under the maximum saturation flux density of 1.2T and different frequencies 20, 30, 40, 50, 100, 150, 200Hz show that the electromagnetic losses is about 0.629 W/kg when frequency is 20 Hz, while it is 18.437 W/kg when frequency is 200 Hz. It is obvious that electromagnetic losses increase rapidly with the increasing of magnetic field frequency. The frequency has a great influence on electromagnetic losses. The amplitudes of magnetic permeability under frequencies 20, 30, 40, 50, 100, 150, 200 Hz are 6140,6123,6084,6049,5837,5194,4328. The results show that hysteresis increases with increasing of magnetic field.