U.S. Ambassador to China Gary Locke, who won plaudits for his low-key style and for cutting visa waiting times for Chinese citizens entering the United States, announced Wednesday that he will step down early next year to rejoin his family in Seattle.

Locke, the first Chinese American to hold the Beijing post, might be best remembered in China for a photograph taken even before he arrived in 2011 that shows him with his young daughter at the Seattle airport, wearing a backpack and trying to pay for coffee with a coupon. The image circulated widely on social media, with many Chinese concluding that Locke, who was also seen flying economy class, was much more down-to-earth and less reliant on publicly funded luxuries than their own officials.

The biggest tests Locke faced as ambassador came in 2012. In February, a high-profile police chief in the southwestern city of Chongqing sought refuge in a U.S. consulate. Two months later, a blind human rights activist escaped from house arrest and sought sanctuary at the U.S. Embassy in Beijing.

Locke’s greatest achievement may have been cutting waiting times for U.S. visas to three to five days, down from 70 to 100 days when he took over. Locke said the improvement had “significantly increased Chinese business and travel tourism to the U.S.”

Douglas Paal, vice president for studies at the Carnegie Endowment for International Peace in Washington, said Locke should be applauded for the visa progress. At the same time, he said, it was “not evident” that the ambassador had a grand strategic vision for the U.S.-China relationship.

Gary Locke, nominated to be next U.S. ambassador to China, talks to Post editor Lillian Cunningham about the leadership imperative for US-Chinese relations. (The Washington Post)

Locke suffered somewhat for his Chinese heritage, something that did not necessarily boost his authority with officials here, Paal said. “That plays well in the United States but doesn’t translate in the host environment. They don’t treat you as an equal in China.”

The first major diplomatic standoff during Locke’s tenure involved police chief Wang Lijun, who gave the U.S. Consulate in Chengdu, near Chongqing, information about the murder of British businessman Neil Heywood, unleashing one of China’s biggest political scandals in decades. The case eventually led to the life imprisonment of Chongqing’s leader, Bo Xilai, on corruption charges.

In April, just days before then-Secretary of State Hillary Rodham Clinton arrived in China for an important bilateral dialogue, the blind legal activist Chen Guangcheng was given shelter in the U.S. Embassy in Beijing for six days.

Locke was on vacation at the time, but he hurried back to China to manage the crisis. Again, he won praise for a photograph — this time, showing him holding Chen’s hand as the two entered a hospital. The activist was later allowed to leave China with his family and settle in the United States.

Sun Zhe, a professor in the department of international relations at Tsinghua University in Beijing, said Locke had helped stabilize U.S.-China ties and handled the 2012 situations well by communicating with the governments in Washington and Beijing round-the-clock.

“It is not an easy job to be the American ambassador to China,” Sun said. “Gary Locke is not a shining star, but a simple and unadorned ambassador.”

Locke, a former commerce secretary and governor of Washington state, also focused on promoting U.S. exports to China and on Chinese investment in the United States, which he said had helped create American jobs. But experts said he had never seemed to hold much sway with the Obama administration.

In a statement announcing his departure, Locke said he had also “advanced American values by meeting with religious leaders and human rights lawyers, and visiting Tibetan and Uighur ethnic minorities in Tibet and Xinjiang.”

Embassy officials said Locke decided to leave his post to reunite with his family and ensure that his children could finish their schooling in one place, rather than over concerns about pollution or schooling in China.

“Mrs. Locke and the Locke children moved back to the Seattle area last summer so that the two eldest children could complete their high school education there,” spokesman Nolan Barkhouse said.

Shen Dingli, executive dean of the Institute of International Studies at Fudan University in Shanghai, praised Locke for promoting trade and people-to-people ties, adding that he “showed us how a U.S. minister-level official behaves by taking economy-class flights.” But he said Locke had “caused a twist” in U.S.-China relations when a subordinate allowed activist Chen to take shelter in the embassy in his absence.

Despite that controversy, China’s Foreign Ministry said it appreciated the “positive efforts” Locke had made in promoting bilateral cooperation, including helping arrange a meeting between President Xi Jinping and President Obama at the Sunnylands estate in California in June.

That meeting, said spokesman Hong Lei, “established the direction of building a new type of relationship between great powers.”

Liu Liu contributed to this report.