Before he headed to a formal dinner with China's President Hu Jintao, he set aside time to see his half brother, Mark Ndesandjo, and Ndesandjo's wife, who had flown up from the southern boomtown of Shenzhen where they live.
Describing the meeting Monday as "overwhelming" and "intense," Ndesandjo told The Associated Press in an interview Wednesday that he had long anticipated the chance to welcome his famous brother to China.
"My big brother, you know I think he was on his way to see the president of China. ... He came directly off the plane, changed some clothes and then came down and saw us. And he just gave me a big hug. And it was so intense. I'm still over the moon on it. I am over the moon. And my wife. She is his biggest fan, and I think she is still recovering," he said with a laugh.
Ndesandjo said he bought tickets to fly to Beijing months ago, hoping to reconnect with his brother. The two last met in January when Ndesandjo attended Obama's inauguration in Washington, D.C., as a family guest.
The three had a long chat, with Obama being introduced to Ndesandjo's wife, a native of Henan, China, whom he married a year ago, he said. He gave few specifics about what they discussed.
"All I can say is, we talked about family, and it was very powerful because when he came in through that door, and I saw him and I hugged him, and he hugged me and hugged my wife. It was like we were continuing a conversation that had started many years ago," he said.
Ndesandjo is tall and slim, with close-cropped hair that gives him a strong resemblance to his brother.
The two men did not grow up together. Ndesandjo's mother, Ruth Nidesand, was Barack Obama Sr.'s third wife. Just before he arrived in Beijing on Monday, Obama had been in a townhall-style meeting with students in Shanghai, where he joked with the audience that a family gathering in his home "looks like the United Nations."
President Obama's father had been a Kenyan exchange student who met his mother, Stanley Ann Dunham, a Kansas native, when they were in school in Hawaii. The two separated two years after he was born.
The senior Obama later met Ndesandjo's mother as a graduate student at Harvard University, and the two returned to live in Kenya, where Mark and his brother, David, were born and grew up. David later died in a motorcycle accident.
Obama's mother went on to marry an Indonesian man and he spent part of his young life in Jakarta. His sister, Maya Soetoro-Ng, is half-Indonesian and her husband is Chinese-Canadian.
Since 2001, Ndesandjo has been living in the booming southern Chinese city of Shenzhen near Hong Kong and earns a living as a marketing consultant. For most of that time, he has maintained a low profile, with few people knowing his connection to the U.S. president.
But two weeks ago, he went public to launch a new novel, a semi-autobiographical book called "Nairobi to Shenzhen" that features a protagonist who is the son of a Jewish mother and an abusive father from Kenya.
The book, available over the Internet by the self-publishing company Aventine Press, was partly meant to raise awareness about domestic violence, he said. His father beat him and his mother when they were living in Kenya, Ndesandjo said.
"For a long time, I had serious, serious reservations about using that name (Obama) because of the hurt I experienced," he said. Though he wanted to maintain his privacy, he decided to write the novel because "there are certain things you can do and you really should do because you know it will help people."