An L-threonine-producing Escherichia coli in which a promoter of a phosphoenolpyruvate carboxylase (ppc) gene on the chromosome is substituted with a promoter of a cysteine synthase ( cysk ) gene and a method of producing L-threonine by using the same are disclosed. The recombinant Escherichia coli may produce L-threonine in a high yield, and thus may be widely used in medical, pharmaceutical, and feed industries, particularly for an animal feed.