"In your deliberations over the days ahead, you have the encouragement of the whole Commonwealth to maintain this vital tradition," she said.
"The results of this meeting may be global in impact or simply touch a single individual even imperceptibly. But in every respect I trust the results will be positive and enduring."
As the representatives of the 54-nation bloc which stretches over six continents and ranges from impoverished nations to wealthy, advanced economies, watched, the queen recited an Aboriginal proverb "which is itself enduring".
"We are all visitors to this time, this place. We are just passing through. Our purpose here is to observe, to learn, to grow, to love. And then we return home," she said before officially declaring the summit open.Dressed in a powder blue silk jacquard dress and coat with navy trim adorned with a brooch which previously belonged to her late mother, the queen said the 2011 CHOGM promised "to bring new vibrancy to the Commonwealth".
"I wish heads of government well in agreeing further reforms that respond boldly to the aspirations of today and that keep the Commonwealth fresh and fit for tomorrow," she said.
"In these deliberations, we should not forget that this in an association not only of governments, but also of peoples."
Thousands have thronged public events in Canberra, Melbourne and Brisbane to see the queen, with scores bringing flowers and momentoes to her, with the suggestion this could be her last visit to the distant realm.
"We are grateful to the people of Australia for their welcome," the queen said in her address.