In 2015, China banned harvesting organs from executed prisoners, ending a practice long criticized by the international community. Since then, citizens' voluntary donation of organs has become the only legitimate source for organ transplants in China. How has the reform been working?

Chinese health officials shared the country's organ donation principals with international experts at a conference in Beijing.

Organ donation in China must be voluntary and unpaid. No hospitals or doctors can decide on who will be the recipient of a specific donated organ. And, living organ donations are strictly limited between relatives.

"China's regulations, systems and standards for organ transplantation have been brought in line with WHO guiding principals," Director General of WHO Margaret Chan said.

In the first nine months of this year, China completed nearly 3,000 organ donations, marking a 50 percent increase from the same time last year. Now, China's annual number of organ donations ranks first in Asia, and third in the world after the United States and Brazil.

"We did an online survey with more than 41,000 respondents. Forty-five percent of them said they were willing to become organ donors. The remaining 55% said they still know little about our system. They don't trust us yet. They need a sound legal system. They need an end to organ trading," Huang Jiefu, director of China Organ Donation & Transplantation Committee, said.

In addition to technical challenges, organ donation and transplantation face social, ethical and legal issues. The question is: Who has priority to receive an organ?

China has established a computer allocation system called the China Organ Transplantation Response System, or COTRS, to ensure transparency and fairness. The system works on the principals of urgency, compatibility and patient need. And, it has allocated 17,000 organs since the establishment in 2013.