Massive demand has caused the ticketing system for the 2008 Beijing Olympic Games to crash.
China would like to stage the "perfect" Olympic Games
Organisers said an average of 200,000 applications were being submitted through the website every minute.
There were also long queues outside banks selling tickets, and telephone lines were jammed.
This second round of sales has made 1.8m tickets available to people in China, following a lottery in June which allocated 1.6m tickets.
Tickets are being sold on a first-come-first-served basis through the official ticketing website, run by the Beijing Organising Committee for the Olympic Games (Bocog).
The website received 8m hits in the first hour alone.
But by 11am local time (0300GMT) just 9,000 of the tickets had been sold.
Tickets were also on sale by phone and at designated Bank of China branches across the country.
Queuing at dawn
Huge queues built up outside the banks, with some customers starting to queue hours before the branches opened.
At one branch in central Beijing, just four customers were served before the computer system crashed.
The bank staff told everyone else in the queue to go home
"We can't process any orders here," a bank employee told the French news agency AFP. "The whole system is down, I don't think you can buy any tickets in any way right now."
China wants to stage the perfect Olympic Games and would like every seat filled with cheering, patriotic supporters.
Organisers warned that people hoping to see the most popular events, including gymnastics, table tennis and the opening and closing ceremonies, may be disappointed.
A statement on the Bocog website asked prospective buyers to be patient and not to keep clicking on the site.