Abstract: The ferrite dominated kicker magnet whose main function is to produce uniform pulsed magnetic field is one of the crucial elements in injection system improvement task of national synchrotron radiation lab phase Ⅱ project. The mathematical model and analysis concerned in eddy current of kicker's core in the designing is presented. The result of quantitative analysis demonstrates that, to determine the conductivity of ferrite material and parameters of magnetic core reasonably can eliminate the effects of eddy current on the magnetic field properties. The results of pulsed magnetic field measurement of kicker magnets show that, the design of kicker magnets of HLS storage ring is reasonable.