Abstract: The effect of cell shape of mushroom-like AMC(Artificial Magnetic Conductor) to its reflection phase characteristic is analyzed in this paper,and it is found that the reflection phase band-gap is relative to only the size in the direction parallel to polarization direction of incident plane wave.Therefore the strip-type AMC structure is introduced,and its reflection phase band-gap and surface wave band-gap are analyzed.Different surface wave characteristics compared with mushroom-like structure are found.