Conventional rotational invariants of Tchebichef moments are represented by rotational invariants of geometric moments

therefore the drawbacks of geometric moments

such as high degree of information redundancy and sensitive to noise

are inevitable. New rotational invariants of Tchebichef moments are proposed in this paper. Uusing the properties of falling factor，the proposed moments are transformed to linear combinations of Tchebichef central moments which can be evaluated by Tchebichef moments directly. Experiments show that our descriptor outperformed the conventional descriptor in rotational invariants.