The launch ceremony has taken place at the Chiang Rak Noi Station in central Thailand's province of Ayutthaya.
This is where the project's Operation Control Center will be located.
Saturday's ceremony comes exactly one-year after the Thailand-China Memorandum of Understanding for Railway Cooperation was first inked, and three months after the signing of an inter-governmental agreement on railway projects.
Thai deputy Prime Minister Prachin Chantong.
"Today last year, we signed an MOU between Thailand and China in cooperation on this train project. It's been only one year since our commitment and we can make it clear that this project is certainly going forward."
The 845-kilometer-long line will pass through 10 Thai provinces and link the capital Bangkok with the northeastern city of Nong Khai, which is located near the northern Thai border with Laos.
The trains themselves are designed to operate at a top speed of 180 km per hour.
Thai Railways Minister Wutthichart Kalayanamitr says the link, once completed, will create significant economic benefits for the country.
"It will benefit Thai people, especially those living along the railway line, by creating job opportunities and increasing their income, as well as pushing forward tourism development and cutting transportation costs."
The project itself is scheduled to be finished by 2018.
Both China and Thailand are financing the project, which is going to cost close to 470-billion US dollars when finally complete.
The link is part of a planned rail corridor running from Yunnan's capital Kunming all the way to the Malaysian peninsula.
Chinese state councilor Wang Yong.
"Once the railway takes shape, Thailand will become a key transportation hub of Southeast Asia, facilitating both the socioeconomic development of Thailand and its trade and exchange with China."
It's expected the railway will help an additional 2-million Chinese tourists make their way to Thailand every year.
Construction is expected to begin this coming May.
For CRI, this is Li Jianhua.
