Liao Xiaohua, a 43-year-old vegetable picker in east China's Jiangxi Province, was still working several days before Spring Festival which falls on Friday.

Liao works at a vegetable base supplying Hong Kong, which is nearly 900 km away. She has to be very careful when picking the fragile and wet leafy vegetable as many Hong Kong people have special requirements to its length and the number of leaves.

Thirty hours after being picked the vegetable will be on a plate -- a dish known as Choy Sum in Oyster Sauce.

More than 90 percent of the vegetables in Hong Kong markets are supplied by the mainland. Vegetable demand in Hong Kong soars during Chinese New Year, meaning a busier time for workers like Liao.

Liao has never been to Hong Kong. But she does know from popular TVB (local broadcaster) dramas that it is a prosperous city and a place which was occupied by foreign countries and returned to the motherland in 1997.

Seventeen years on, the city's prosperity and stability have been consolidated under the mutual-beneficial cooperation between Hong Kong and the mainland.

"The vegetable I pick is constantly transported to Hong Kong. I hope one day I can go there and have a look," said Liao.

A HIGH DEGREE OF OPENNESS

With the release of preferential policies to Hong Kong during the past decade, the mainland has helped with Hong Kong's harmony and development.

Guo Wanda, vice president of the National Research Society on Hong Kong and Macao Affairs, listed some important policies, including the Mainland and Hong Kong Closer Economic Partnership Arrangement (CEPA) and key measures in promoting mainland tourists traveling to Hong Kong and offshore renminbi (RMB) trading.

Signed in 2003, CEPA is one of the mainland's earliest free trade protocols and Hong Kong's first agreement regarding free trade. The CEPA and its following 10 supplements were designed to reduce or exempt tariffs and realize trade liberalization and investment cooperation between the mainland and Hong Kong.

"CEPA represents the mainland's highest opening-up level to the outside world," said Sun Tong, deputy head of the Ministry of Commerce's department of Taiwan, Hong Kong and Macao affairs.

According to the standards set by the World Trade Organization (WTO), free goods trade has been accomplished between the two sides, while free services trade is expected to be achieved by the end of 2015.

Customs figures show that tax abatement for Hong Kong exports under the CEPA has totaled 3.98 billion yuan (657 million U.S. dollars) since 2003.

Hong Kong consolidated its status as an international financial hub with its RMB deposits reaching 1 trillion yuan by the end of 2013. It is also the world's largest offshore trading center for the RMB.

The increasing number of mainland tourists gives a big boost to Hong Kong's travel industry, which employs 620,000 people, one sixth of its workforce. In 2013, more than 70 percent of Hong Kong's visitor arrivals came from the mainland.

Mainland individual tourists also helped Hong Kong's total retail sales double that of ten years ago, said Caroline Mak, chairwoman of Hong Kong Retail Management Association.

For Hong Kong, the rising mainland is not only a powerful backer, but also a promising market for Hong Kong businessmen to tap into.

Six Hong Kong-based banks, including HSBC and Hang Seng Bank, have opened 61 sub-branches in nearby Guangdong Province. More Hong Kong businessmen have taken their brands to second-tier cities in the mainland.

Meanwhile, Hong Kong has become the first choice for mainland enterprises seeking to go public overseas as well as a start-point for mainland security and futures agencies to extend business abroad.

A total of 182 enterprises from the Chinese mainland were listed in Hong Kong by the end of 2013, holding 57 percent of the total market value of Hong Kong shares. Their turnover in the Hong Kong stock exchange took up about 70 percent of the total volume.