Tim Cook (left), CEO of Apple Inc talks with Liu Qing, president of Didi Chuxing on May 16 in Beijing. [Photo: twitter.com / tim_cook]

Neil Shah, research director at market research company Counterpoint Technology Market Research, said Cook's visit to China, the recent investment in Didi and Cook's promise to help Chinese developers add to the fact that "China is and will remain to be the most important market for Apple".

"Didi's scale and reach is a great channel for Apple to integrate its core services such as Apple Pay and Apple Music into the Didi vehicles and get a share out of the customers' lives," Shah said.

Didi currently handles more than 11 million rides a day and serves about 300 million users in China.

"We believe apart from meeting with Didi, strengthening ties with government and checking the Apple stores' rollout progress are other reasons for this trip," Shah added.

Apple opened seven stores in China during the quarter ending in March and will open five more to take the tally to 40 by the end of June, signifying the importance of the Chinese market for the company.

Liu Zheng contributed to this story.