A term sheet for the unit of e-commerce giant JD.com has shown it's seeking to raise up to $3.5 billion.
That would make it Hong Kong's biggest initial public offering of the year.
And the deal could value JD Health at nearly $29 billion.
It comes during a good year for China's healthcare platforms which have seen their popularity surge in the wake of the pandemic.
By comparison, its biggest competitor, Alibaba Health Information Technology, has a market capitalisation of around $34.6 billion.
According to its draft prospectus, JD Health is the largest online healthcare platform in China by revenue, logging $1.6 billion last year.
One analyst said the fundraising is set to lay the groundwork for greater competition in China's healthcare market.
JD Health shares are expected to start trading on December 8th.
The company did not immediately respond to a request for comment.