He praised the Chinese president, Xi Jinping, for saying recently that he would take steps to stop the country's domestic ivory trade. Conservationists say the trade enables the laundering of illegally imported ivory.
Prince William recorded a speech for Chinese state television on Monday, calling on China to stop the illegal ivory trade, as the country's president, Xi Jinping, begins a trip to the UK.
The Duke of Cambridge made the comment in a speech to a small audience at King's College London that included the broadcasters Sir David Attenborough and Bear Grylls. It will later be shown to millions on Chinese television station CCTV1, The Guardian reports.
He said: "We have to accept the truth: that consumers are driving the demand for animal body parts, for art, for trinkets, or for medicine. Only we as consumers can put the wildlife traffickers out of business.
"It is time to talk about the growing human demand for illegal wildlife products that drives the trade and makes it profitable."
50 elephants killed every day
He said the rate of killing – three rhino and more than 50 elephants a day in South Africa – meant that children born this year, such as his daughter Charlotte, would see the last elephants and rhino die before their 25th birthday.
The prince visited an elephant sanctuary in Yunnan province during a royal visit to China in March, where he praised the country's contribution to protecting wildlife in Africa. But without singling out China, he said more could done to reduce demand, which comes largely from south-east Asian countries.