Hsu assumed the position of Mayor of Hsinchu City starting 20 December 2009 after winning the 2009 Republic of China local election on 5 December 2009 under the Kuomintang.
On 25 June 2013, Hsu received John Leung, the Director of the Hong Kong Economic, Trade and Cultural Office (HKETCO) in Taiwan with his colleagues. They had a meeting which were also attended by the Hsinchu Chamber of Commerce and Importers and Exporters Association of Hsinchu City.[3]
In 2014, Hsu joined the 2014 Republic of China local election as a Kuomintang candidate for Mayor of Hsinchu City, going against his rival Lin Chih-chien from Democratic Progressive Party and independent candidate Tsai Jen-chien. His campaign slogan was Intelligence, happiness, health and security. His campaign promises were connecting Hsinchu city to Provincial Highway 61 and Jiadong Township in Pingtung County, calling for the relocation of CPC Corporation oil reserve building for its land to be used as the new city government center and city council building, relocating the urban center and turn the old town area into a historical and cultural tourist area, building an off-ramp from the Wuyang Expressway to Hsinchu City center, establishing a hospital for women and children and expanding the Hsinchu City branch of the National Taiwan University Hospital.[4] Hsu however lost to DPP candidate Lin Chih-chien.[5]
| 2018 Kuomintang Hsinchu City mayoral primary results |
|---|
| Candidates |
Place |
UDN |
Apollo Survey & Research |
TVBS |
Aggregated Result |
| Hsu Ming-tsai |
Nominated |
40.55% |
42.89% |
42.63% |
42.02% |
| Lin Geng-ren |
2nd |
36.15% |
34.63% |
34.62% |
35.13% |
| Li Guo-zhang |
3rd |
23.30% |
22.48% |
22.75% |
22.84% |
| 2018 Hsinchu City mayoral results[6] |
| No. |
Candidate |
Party |
Votes |
Percentage |
|
| 1 | Hsieh Wen-chin (謝文進) |  Independent | 44,101 |
20.31% |
|
| 2 | Li Chi-qun (李驥羣) | Independent | 705 |
0.32% |
|
| 3 | Huang Yuan-fu (黃源甫) | Independent | 3,603 |
1.66% |
|
| 4 | Hsu Ming-tsai |  Kuomintang | 60,508 |
27.87% |
|
| 5 | Kuo Jung-jui (郭榮睿) | Independent | 574 |
0.26% |
|
| 6 | Lin Chih-chien | Democratic Progressive Party | 107,612 |
49.57% |
 |
| Total voters | 338,323 |
| Valid votes | 217,103 |
| Invalid votes | |
| Voter turnout | 64.17% |
.svg){kind=small}
.svg){kind=icon}
