By Michael Bristow
BBC News, Beijing
Mr Wang urged people to come to China and see things for themselves
China has vigorously defended itself against accusations that it has not fulfilled promises it made when it bid for the Olympic Games.
Top Beijing Olympic official Wang Wei said the Olympics would allow China to open up further to the outside world.
He was responding to criticism about China's pledges on issues such as human rights and media freedom.
International Olympic officials have voiced disapproval over the detention of a UK journalist covering a protest.
China has faced a barrage of criticism in the lead-up to the Games on a range of issues, including air pollution.
Critics also say China has failed to improve human rights and accuse it of reneging on a pledge to provide complete media freedom to report the Games.
But in an impassioned speech, Wang Wei, executive vice-president of the Beijing organisers, dismissed the bad publicity.
Speaking at a press briefing, Mr Wang said that when he was secretary-general of the Beijing Olympic bid committee, he was "confronted with many questions".
Police prevented journalists filming a pro-Tibet protest on Wednesday
"I did say that the Olympic Games coming to China will help China open up further and reform better," he said.
The fact that China had set up protest areas for its citizens during the Olympics showed it was heading in the right direction, he said.
"I think China has been stepping forward, and if you ask the ordinary Chinese on the streets they will give you the same answer," he said.
"Everybody is happy. People are optimistic about their own future. That is a fact."
Mr Wang went on to attack what he termed the small number of people who criticised China. "That does not mean we are not fulfilling our promise," he said.
Visitors coming to China for the first time would see a different country to the one represented in films and newspapers, he added.
"People will see better for themselves what China is like," he said.
Despite the comments, International Olympic Committee spokeswoman Giselle Davies, sitting next to Mr Wang, said journalists should be able to do their jobs unhindered.
Her comments come after a British journalist was briefly detained while trying to cover a pro-Tibet protest near the main Olympic venues.
"We donít want to see it happening again," she said, referring to the detention.