"People from both sides of the strait are longing for peace ... Mainland leaders have also showed sincerity in improving cross-strait relations," Soong told reporters at the airport upon return from his nine-day visit to China.
He added Friday that China had announced a number of concrete steps to boost bilateral ties, including a promise to push for direct air links in 2006.
"Peace is in our own hands," said Soong, chairman of the People First Party. Pushing for independence for Taiwan, he warned, could destroy peace prospects.
China sees Taiwan as part of its territory awaiting eventual reunification since they split at the end of the civil war in 1949 and has regularly threatened to invade if the island moves towards formal independence.
Soong also said Taiwan's President Chen Shui-bian had "promised not to promote independence through constitutional amendments".
He was referring to Saturday's elections, in which voters were to elect a 300-member National Assembly to decide on a package of constitutional reforms, including whether referenda could be used to amend the constitution.
Beijing has opposed referenda, which it sees as a step Taiwan could take toward declaring formal independence.
Saturday's poll is seen as a litmus test of support for the island's independence-minded leaders and the opposition, who favour closer ties with China, following recent visits there by two opposition leaders.
Soong's trip followed the historic visit to China by Lien Chan, chairman of the main opposition Kuomintang party.
Both Lien and Soong said their trips were meant to bridge differences between the two rival governments and pave the way for peace talks.
Beijing also agreed to simplify visa application procedures for Taiwanese and to offer incentives to Taiwanese