Artificial magnetic conductor (AMC) is a kind of periodic structures and it introduces a zero degrees reflection phase shift to incident wave. In order to reduce size of artificial magnetic conductor and increase their working bandwidth, InP process is used to design AMC in this paper. InP material has advantages of large forbidden bandwidth, high electron mobility, negative resistance effect etc. AMC based on InP process has been analyzed and results show that the proposed AMC has a good bandwidth compared with that of CMOS process for its smooth reflection phase variation and its whole size is greatly reduced.