The present invention discloses a protein relating to pig fat deposition and the coding gene as well as application of the protein. The pig fat deposition related protein is of one of the following amino acid residue sequences: 1) The No 1 sequence in the sequence table; 2) the No 1 amino acid residue sequence with one or more than one amino acid residue substituted or lost or added; The protein is related to pig fat deposition. The protein relating to pig fat deposition and the correspondent coding gene can be used to detect the body traits such as suet rate, inner-lipid rate, the back-fat thickness between the 6 to 7 inter-ribs and the average back-fat thickness of the pig that can reflect the fat deposition capability. Therefore, the present invention provided a new genetic marker for the pig molecule breeding, and plays an important role in the pig breeding.