Apple Inc's fourfold growth in revenue in China in the January-March quarter contributed about 20 percent of the total income for the world's No. 1 technology company.

Its revenue in China was US$7.9 billion due to booming sales of the iPhone, iPad and Mac computer in the world's biggest phone market, Apple said yesterday.

The sales of the iPhone were five times the level a year ago after the launch of the iPhone 4S on China's mainland in January while the addition of China Telecom as an iPhone partner in March also helped. Apple's first iPhone carrier is China Unicom.

"Apple is growing rapidly on the mainland through iPhone sales," said Wang Ying, an analyst at Beijing-based Analysys International.

Apple's Chief Financial Officer Peter Oppenheimer said in an earnings conference call that the company continued to see tremendous momentum in the Chinese market.

Apple's global iPhone sales soared 88 percent in the quarter while the global smartphone sales grew 42 percent in the period, research firm IDC said.

By the end of last year, Apple's share of the mainland's smartphone market was 5.7 percent, still trailing Samsung's 22 percent and Nokia's 15.3 percent, Analysys said.

Globally, Apple's revenue for the quarter was US$39.2 billion, an annual rise of 59 percent.

Apple may debut the new iPad on the mainland next month, media reported recently.