The strategic partnership will feature retail offerings of Yoox Net-a-Porter Group S.p.A. (YNAP), the online luxury retailer, to Chinese consumers.
Under the partnership, YNAP and Alibaba will establish a joint venture to launch two mobile apps for the Net-a-Porter and Mr Porter multi-brand, in-season online stores for consumers in China.
"Chinese customers at home and abroad are an increasingly important customer base for Richemont and for the broader luxury industry," said Richemont Chairman Johan Rupert.
"Our digital offering in China is in its infancy and we believe that partnering with Alibaba will enable us to become a significant and sustainable online player in this market."
Luxury companies, normally known for their plush brick-and-mortar boutiques, have been trying to increase their online retail presence in China, one of the world's largest markets for expensive watches and jewellery.
JD.com Inc, China's number 2 e-commerce firm, last year invested nearly $400 million in fashion retailer Farfetch UK to expand its luxury offerings. It also launched Toplife, a platform which aims to woo luxury buyers with same-day deliveries and services, including extra clean and secure warehouses with special air filters.
It rivals Luxury Pavilion, a similar portal backed by Alibaba's Tmall platform and features products from fashion groups such as Burberry.
Cartier owner Richemont, which has been trying to beef up its online presence, this year bought Watchfinder.co.uk Limited, an online platform to research, buy and sell premium pre-owned watches.
It also took full control of Yoox Net-a-Porter to compete better in an expanding online market for luxury goods, after initially merging its Net-a-Porter online fashion business with Italy's Yoox in 2015.
By Michael Shields and John Revill; editor: Maria Sheahan.