In 2005, he arranged the meeting between Soong with then-General Secretary of the Chinese Communist Party Hu Jintao after communicating with the then-Director of Taiwan Affairs Office Chen Yunlin.

[7] In end of June 2013, Chang joined a delegation led by Lin Join-sane, Chairman of Straits Exchange Foundation (SEF), to visit Shanghai from Taiwan for the Cross-Strait Service Trade Agreement signing.

Meanwhile, 80 Chinese Mainland industries will be opened to Taiwanese investments, ranging from finance, retail, electronics, publishing and travel sectors.

[citation needed] In early February 2014, Chang was appointed to be the vice chairman and secretary-general of the Straits Exchange Foundation (SEF), replacing Kao Koong-lian who had earlier on tendered his resignation.

[12] Few days later on 21 August 2014, Chang held a press conference in Taipei responding to an allegation he received from the government that he had leaked national secrets to Mainland China thus that he was actually sacked from the MAC by Minister Wang Yu-chi.

[citation needed] The Investigation Bureau of the Ministry of Justice even suspected that Chang had been recruited as a spy for the Chinese Communist Party.

In a different occasion, President Ma Ying-jeou threw his approval behind MAC Minister Wang Yu-chi's decision to sack Chang.

[18] On 10 February 2015 the Investigation Bureau dropped the charges against him, and Wang Yu-chi immediately announced his resignation from his post as MAC minister, stating that he disagreed with the decision but would respect it and take responsibility.