Mr Ma has proposed a formal peace treaty with China
The opposition candidate in Taiwan's presidential election, Ma Ying-jeou, has won a clear victory.
Official results put Mr Ma, of the Kuomintang party, nearly 17 percentage points ahead of Frank Hsieh of the ruling Democratic Progressive Party.
Both candidates advocated closer economic ties with China, but differed over the pace and degree of change.
Mr Ma pledged to strengthen commercial ties more quickly than Mr Hsieh, who took a more cautious approach.
He will succeed arch-nationalist Chen Shui-bian, who steps down in May.
Over 17 million people were eligible to vote and turnout figures are expected to be high.
'No war'
Final official results from the central election commission give Mr Ma 58.45%, while his rival Mr Hsieh trails on 42.55%.
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A huge crowd cheered and whistled at opposition Kuomintang headquarters, and firecrackers were set off across the capital, Taipei, as the preliminary results were reported on local TV networks.
"People want a clean a government instead of a corrupt one," said Mr Ma, quoted by AP news agency.
"They want a good economy, not a sluggish one. They don't want political feuding. They want peace across the Taiwan Strait. No war."
The Kuomintang also won a sweeping victory in parliamentary polls in January, and now commands two-thirds of seats there, so he has a strong mandate to implement his policies, says the BBC's Caroline Gluck in Taiwan.
Supporters at Mr Hsieh's base were subdued, with many in tears.
"Don't cry for me today," Mr Hsieh said according to AP.
Mr Hsieh's supporters were despondent
"Although we lost the election, we have a more important mission. The torch of democracy should not be extinguished."
Both referendums on whether Taiwan should join the United Nations failed.
Far too few voters participated in the referendum to validate the results - as at least 50% of eligible voters were needed.
One of the referendums - which asked whether the island should apply to join under the name Taiwan, rather than the island's official name, the Republic of China - had proved particularly controversial.
Economic revival
Many Taiwanese waiting to cast their votes identified the faltering economy as their top priority.
Mr Ma put the promise of an economic revival at the centre of his election campaign.
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He had set ambitious growth targets - which some analysts say will not be met, unless his second pledge, to establish much closer economic ties with China, is also fulfilled.
China says that Taiwan is part of its territory, although the two have been separately governed since 1949, and China has never ruled out using force against the island should it move towards formal independence.
Under President Chen, ties were restricted because of his pro-independence stance.
Mr Ma wants to act quickly, introducing direct flights to the mainland and easing restrictions on investment in China. He has called for the creation of a "common market".
He has also proposed the agreement of a formal peace treaty with China.
'Second Tibet'
His rival was more cautious, promising dialogue with China while pledging to defend Taiwan's sovereignty.
The recent unrest in Tibet also become an election issue, with both men speaking out against Beijing.
Earlier this week Mr Ma talked of a possible Olympic boycott if the situation there deteriorated, though he said on Friday he would not "push the issue to the extreme".
Mr Hsieh, meanwhile, had argued he would be the best protector of Taiwan's sovereignty, warning that his rival could make Taiwan a "second Tibet".
