"I will use peace as a beacon and democracy as a compass. In the complex geopolitical situation, I will brave the winds and the waves to lead Taiwan steadily forward," he said, speaking at one of Taipei's most well-known hotels.
The DPP conference coincided with a rally for legal reform and against high real estate prices organized in downtown Taipei in front of the presidential office by internet celebrity Holger Chen and Huang Kuo-chang, a former lawmaker for the New Power Party, a small opposition group.
While billed as nonpartisan, both Ko and Hou Yu-ih of Taiwan's main opposition party the Kuomintang took part, though they did not share the stage together. Terry Gou, the retired founder of major Apple supplier Foxconn, also attended.
Ko, to cheers from the several thousand strong crowd on a scorching hot day, said it was not a protest, despite the anger directed at the DPP by speakers and many in the crowd.
"This is a day to promote Taiwan's progress," Ko said. "We're not here to protest anything or to create antagonism."
Hou, running a distant third in the polls, was less well received and got some boos when he spoke.
Taiwan's opposition parties frequently criticize the government for interfering in what should be independent bodies like the media regulator, moves the government denies.
