A EBG（Electromagnetic Bandgap） structure was prepared based on the theory of the high impedance surface photonic crystal and the HFSS emulating results. The measurement result showed that the bandgap of the EBG structure was in the Ultra Wideband range. The designed structure was fabricated by a method of low temperature co-fired ceramics technology（LTCC） using ceramics as the matrix and silver as the coils. The micro-structure was analyzed by microscope and scanning electron microscope which showed that these two kinds of materials were well connected. A bandgap between 4GHz~5.5GHz was found by the Vector Network Analyzer which was accord to the emulation.