Abstract: A novel catalytic material based on collagen fiber loaded with active MnO₂ was prepared. During the preparation, the collagen fiber was first modified with Mimosa tans and then reacted with KMnO₄ to yield the material. The morphology and structure of this material were analyzed by means of DSC, XRD and SEM, and its catalytic oxidation of formaldehyde gas was investigated at room temperature without illumination. The results showed that the material was in ordered fibrous state and MnO₂ particles were well-dispersed onto the surface of collagen fiber. The material exhibited good catalytic-activity for the formaldehyde gas oxidation. The formaldehyde removal efficiency could reach 97% within 6 hr under the given conditions. The recycling test presented satisfied removal efficiency after the reuse of 8 times.