In a statement released by the U.S. embassy in Beijing, Locke said he wished to be with his family, who have already moved back to Seattle.
Locke's wife, Mona Locke, wrote last month about the family's decision to move back to Washington state from Beijing, in a column published in the Seattle Times.
"Gary and I wanted our family to have a place to call 'home,'" she said. "We needed a home where our kids could attend local schools, make lifelong friends, and learn to value community and help others."
Gary Locke served as U.S. secretary of commerce and two terms as governor of Washington. He Became the ambassador to China in August 2011, and is the first Chinese-American to hold the post.
"As I reflect on my tenure as ambassador, I do so knowing that U.S.-China relations continue to grow stronger,” he said in his statement. “While our bilateral relationship is a complex one, I remain confident in the ability of our leaders to manage differences and increase cooperation in areas of mutual concern to the benefit of not just our two great peoples, but the entire world.”