'Ours was a love marriage, but many marriages are arranged through brokers, for money, and the partners barely know each other. They have more difficulties.'

Ms Yang is one of more than 350,000 foreign and mainland wives of Taiwanese men. These women are the biggest wave of immigrants to Taiwan since the arrival of Chiang Kai-shek, his government and his army in 1949.

The influx began in the mid-1980s, when the government began granting residency rights to foreign spouses and, since the mid-1990s, spouses from the mainland. So-called 'foreign wives' have more children than local women, their children accounting for about 13 per cent of all births.

But accepting outsiders and the tens of thousands of children of their marriages is proving a challenge to a society unaccustomed to non-Chinese immigrants.

The wave of wives also reflects the increasing freedom of Taiwanese women, more of whom graduate from university than men. Many choose not to marry and, if they do, they want fewer children.

It also reflects a polarisation of society, with thousands of men in rural areas, in low-paying jobs or unemployed, unable to find a wife at home because the factories where they used to work have closed and moved to the mainland or abroad and the jobs that remain require high levels of skill and training.

The demand for wives has driven a boom in business for the brokers who find foreign wives. Their fees start at NT$200,000 (HK$47,180). 'We take two groups a month to the mainland, with 10 to 20 men, for 10 days, with a success rate of more than 80 per cent,' said a broker named Tsai. 'The total cost is NT$300,000. Few men in their lives have the opportunity to choose between 30 and 40 women. We organise this for them in one day.'

Other brokers take suitors to Vietnam, Cambodia, Indonesia and other countries in Southeast Asia.

The matchmaking has produced some unhappy endings. In 2000, Ah-ying, a third-generation ethnic Chinese woman from Ho Chi Minh City, met a Taiwanese man and his son, 24, through a Vietnamese marriage agency and three days later agreed to marry the son. His family paid NT$200,000 to the matchmaker, with a small proportion going to her parents.

'Perhaps because of the language barrier I did not realise until we had lived together for three months that he had a slight mental deficiency,' said Ah-Ying, a Cantonese-speaker who had to learn Mandarin. She did the household chores and looked after a family shop. In 2002, she gave birth to a healthy boy but in 2004 was thrown out by her husband's family for no reason. Her husband gave her no support, although she was allowed to see her son twice a week.

With the help of an NGO, she obtained a Taiwanese identity card and now lives on her own, earning NT$20,000 a month at a Taipei electronics plant while she fights for custody of her son.

In another case, Bopha, 18, a rice farmer from Svay Rieng province in Cambodia, met her husband through a marriage broker in her village who said the man was a rich bachelor. In Taiwan she discovered she was the second wife. She was not allowed out of the house where she cared for an elderly woman. 'I was ... a housekeeper with no salary. It was hell.' She was also rescued by a local NGO.

In another case a Taiwanese man was desperate for a child after 11 years of marriage, but did not want to divorce his wife because of her infertility. Through a broker he found a man willing to marry a bride in Cambodia and bring her back to Taiwan for him. After she arrived in Taiwan, she found she was living not with her husband but his friend. She gave birth to twins, whom the friend adopted. Suddenly her husband died and she was repatriated. As the twins had been adopted and her husband was dead, it would be difficult for her to return.

But there are happy endings too. Shen Xiaoju, 51, from Wuhan , met her husband, a retired soldier named Shi, 78, through a friend and they married in 2001. Shi's life has been transformed: Ms Shen looks after him and has turned the lonely man into a sociable soul.

Mr Shi is one of the 500,000 military veterans - 80 per cent of whom are over 65 - whom Chiang brought with him in 1949 with the promise of a quick reconquest of the mainland. Many did not marry because their pensions were too low, they were unskilled and Nationalist soldiers were unpopular among native Taiwanese.

Of the veterans, 21,000 have found wives from the mainland. Half are between 30 and 49 years old and most had been divorced or were widows. It is easier for these women to integrate into Taiwanese society than for women from Southeast Asia as there is no language barrier and the culture and social mores are more familiar.

But they still face major obstacles. They must wait eight years, instead of four for other foreign wives, to obtain a Taiwanese identity card. If their husband dies or divorces them during that time, they must return to the mainland unless they have children under 12 or a mother-in-law over 65.

Ms Shen said she was rejected for job vacancies many times, even though she had a work permit, because of this prejudice.

Most women like her work as cleaners or in restaurants, with worse pay and conditions than their Taiwanese counterparts.

The prejudice comes from media stories about mainland women paying for fake marriages in order to work in Taiwan illegally or becoming prostitutes or 'black widows' in search of money. There is also a steady stream of invective against Beijing's mutterings about forcing reunification and its 900-odd missiles aimed at Taiwan.

In 2003, when the government was debating whether to extend the eight-year wait for ID cards to 12, some said: 'Withdraw the missiles and we will give them ID cards.'

There is also the fear that granting mainland women citizenship will lead to a flood of relatives coming to live in one of the most densely populated places on Earth.

Although women from Southeast Asia can obtain papers more quickly than mainland-born spouses, they face challenges of language and adaptation.

Penghu, a group of islands in the Taiwan Strait, has many Southeast Asian wives. Often poorly educated and with limited Chinese, they cannot monitor the schoolwork of their children, who tend to have poor language skills, heavy accents and are frequently shunned by their peers. Many of their husbands work away from home for long periods, which further hinders their children's education. These women, too, face discrimination.