WHEN Hongkong reverts to Chinese rule in 1997, people will discover they differ greatly from their new masters. But they will share at least one love with mainlanders - shopping. As with Hongkong, consumerism is king in mainland China. With the Chinese economy booming, new stores are opening and decades of pent-up demand is bursting forth. But like the people of Hongkong, mainland Chinese are not interested in purchasing just anything, which is why they kept building up their personal savings - now more than one trillion yuan (about HK$1.35 trillion) - even as the country's state-run enterprises ran up huge inventories. What Chinese consumers seem to want is variety, quality and value for money, and they are willing to pay huge sums. The most ostentatious spenders are the private entrepreneurs whose businesses have boomed since patriarch Mr Deng Xiaoping gave capitalism the go-ahead a year ago. But ordinary Chinese are also finding extra income from the economic reform drive. For example, teachers are being hired as tutors, university professors as corporate advisers, intellectuals receive fees for contributing to newspapers and magazines, and the government encourages moonlighting. Increasing numbers of Chinese are staying in five-star hotels, joining expensive fitness clubs built initially for foreigners, and taking holidays abroad. Mr Yuen Tao, a private trader mainly of Chinese silk clothing, spent two months on holiday in Brazil and the United States last year. ''The [round-trip] air fare was only US$2,200,'' he said. ''It was worth it.'' This was not a once-in-a-lifetime trip for the 28-year-old businessman. He has applied to United Airlines for frequent-flier membership. For the stay-at-homes, new shopping opportunities are springing up. The Beijing department store set up by Yaohan International of Japan and Hongkong has been packed since it opened before Christmas, with as many as 100,000 shoppers a day. SUCH a store is maybe taken for granted in Hongkong. But mainland shoppers, used to grimy state-run department stores with uninviting staff and mediocre produce, are finding it a treat to shop where sales attendants are plentiful and helpful, and the goods varied, even if expensive. Among the most popular items in the electronics department at Yaohan is a Sony portable phone retailing at 2,180 yuan. A Sanyo television, with stand and laser disc unit, will sell for more than 20,000 yuan. Many people have left their names and telephone numbers, asking the store to call them when the sets arrive. ''They have a lot of money, so they think it is cheap,''a sales assistant said. Gold and silver jewellery is in big demand, ''maybe because people want to buy something which will preserve its value,'' a shop manager said. Shoppers are buying Johnnie Walker Black whisky, water beds (at 2,680 yuan ''that isn't expensive'', says a shopper), home exercise machines and imported shoes. According to a local saying, one item which has become de rigueur for Chinese ''fat cats'' is a BMW. Sales of the car doubled last year. Although Chinese are prohibited from buying private cars, many invest in joint ventures with foreign companies, entitling them to import a vehicle free of tax. At the Palace Hotel, the Marguerite Lee shop selling top-of-the-line lingerie is doing ''not very well,'' according to a shop assistant. Still, most of the customers are Chinese and are paying up to 800 yuan for a bra. French luxury bag company Louis Vuitton opened a shop in the same hotel last September, and about a third of its customers are Chinese. ''They get invited to a social gathering and they need something for the occasion,'' manager Ms Abby Ai said. The boutique's prices range from 480 yuan for a name-card holder to 9,000 yuan for a handbag. Expensive Italian menswear company Ermenegildo Zegna set up a boutique in Beijing about 18 months ago expecting most of its customers to be foreigners. But 50 per cent of its clients are Chinese. Prices start at a hefty 1,000 yuan for a shirt, 1,600 yuan for trousers and 7,000 yuan for a suit. But the prices do not scare the Chinese. ''Only western people think the price is expensive,'' said boutique manager Mr Frank Zhang. ''When they are doing business, they [the Chinese] feel more confident in a Zegna suit.''