In his first tweet the billionaire said 500,000 testing kits and one million masks were going to the US.
Alibaba co-founder Jack Ma has sent the first shipment of surgical masks and coronavirus test kits to the US.
The Chinese billionaire tweeted two pictures of the pallets of goods being loaded on to a plane in Shanghai.
Earlier this month he said he would give 500,000 testing kits and one million masks to America.
Mr Ma is also sending consignments of medical supplies to Europe as he called for international cooperation efforts to combat the pandemic.
In his first tweet, Asia's richest person posted photos of a China Eastern Airlines jet being loaded with boxes of coronavirus test kits and face masks as they were shipped to the US.
It comes after the Jack Ma Foundation and the Alibaba Foundation last week announced that they had prepared 500,000 testing kits and 1 million masks to be sent to America.
They also said that they had already donated supplies to other countries including Japan, South Korea, Italy, Iran and Spain, with two million protective masks pledged for distribution across Europe.
The first consignment of 500,000 masks and other medical supplies such as test kits, which was destined for Italy, arrived in Belgium on Friday.
He joins other high-profile technology executives in pledging support for coronavirus research and disease prevention.
Microsoft co-founder Bill Gates, who is the world's second-richest person, has announced that the Bill and Melinda Gates Foundation would give $100m to help efforts to stop the spread of the virus.
On Friday Mr Gates announced that he was stepping down from Microsoft's board to spend more time on philanthropic activities. He said he wanted to focus on global health and development, education and tackling climate change.
Chinese tech giants, including Tencent, ride-hailing company Didi Chuxing, and TikTok owner ByteDance, have all pledged money and resources to fight the coronavirus outbreak. BBC