A new type of computer generated rainbow hologram (CRH), called Lens-less Fraunhofer Computer Generated Eainbow Hologram (LLFCRH), is proposed in this paper.The principle of LLFOEH and the math mode of object wave are analyzed.Based on the information of holograms, the information of ordinary CRH, the redundancy of information and the related techniques for reducint the redundant information are discussed. The experimental results are shown.