The train, carrying household items, garments, textiles, bags and suitcases, will take around 18 days to travel more than 12,000km.
The train, which left on New Year's Day from Yiwu in eastern Zhejiang province, will pass through Kazakhstan, Russia, Belarus, Poland, Germany, Belgium and France before arriving in London.
According to the China Railway Corporation (CRC), London will be the 15th European city to receive freight train services from China.
The CRC said the service would "improve China-Britain trade ties, strengthen connectivity with western Europe, while better serving China's Belt and Road initiative, an infrastructure and trade network connecting Asia with Europe and Africa along ancient trade routes", China’s state-owned news agency Xinhua reported.
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