1. A method of deriving a motion vector predictor (MVP) candidate set for motion vector coding of a block, the method comprising: determining a redundancy-removed spatial-temporal MVP candidate set, wherein the redundancy-removed spatial-temporal MVP candidate set is derived from a spatial-temporal MVP candidate set by removing any redundant MVP candidate; wherein the spatial-temporal MVP candidate set comprises a top spatial MVP candidate, a left spatial MVP candidate and one temporal MVP candidate; checking whether candidate number of the redundancy-removed spatial-temporal MVP candidate set is smaller than a threshold; adding a zero motion vector to the redundancy-removed spatial-temporal MVP candidate set if the candidate number is smaller than the threshold; and providing the redundancy-removed spatial-temporal MVP candidate set for encoding or decoding of the motion vector of a current block.