Su Tseng-chang (Chinese: 蘇貞昌; pinyin: Sū Zhēnchāng; born 28 July 1947) is a Taiwanese politician and the former chairman of the Democratic Progressive Party in 2012-2014. Su served as Premier of the Republic of China from 2006 to 2007 and was Chief of Staff to President Chen Shui-bian in 2004.Su actively campaigned for the Presidential nomination of the DPP, but finished second to Frank Hsieh in the nomination process.