Abstract: A pig myostatin gene locus and uses thereof are provided. Also provided includes an expression cassette comprising a promoter, a foreign gene and a following terminator; the promoter is a DNA molecule as set forth in any of 1)-4): 1) nucleotides at positions 2642-3778 starting from the 5? end of SEQ ID NO. 1 in the sequence listing; 2) nucleotides as set forth in SEQ ID NO. 1 in the sequence listing; 3) a DNA molecule, hybridizing and having the same function with the DNA sequence as defined in 1) or 2) under stringent condition. Experiments show that the pig myostatin gene locus provides a valuable gene source for gene targeting, as well as introducing and expressing a foreign gene at this site.