Liu Jun, deputy director of the State Postal Bureau, said couriers are expected to deliver more than 1 billion packages in the days following Singles' Day on Friday, 35 per cent up on last year, Liu said.
Singles' Day started as Bachelors' Day in China in 1990s.
While the day was then celebrated by drinking and partying, it has been hijacked by online retailers in recent years and become another massive extravaganza in consumption.
Some analysts expect sales to rise by as much as 50 per cent this year, state-run Xinhua news agency reported.