Zhang Jincai, the father, said the only string attached was that "the adopter must ensure that my son gets his surgery."

"I know my dad and my mom mean well for me," the boy whispered to a reporter.

Since September 2008, when the boy was diagnosed with leukemia, the Zhangs have spent 160,000 yuan ($23,440) of borrowed money for medical bills and can't afford the subsequent bone marrow transplant surgery, expensive but badly needed for Zhang junior, whose genetic match with his 15-year-old sister was favorable. The surgery would cost up to 600,000 yuan ($87,900), local daily Eastern Newspaper Today reported Thursday.