Tens of thousands of government supporters poured into the streets of Damascus and other cities, the turnout helped by the government's closing of businesses and schools so that people could take part.
Participants at a huge pro-regime rally in Damascus accused the Arab League of bowing to U.S. pressure.
Violence continued elsewhere, with activists reporting at least 14 people killed in shootings by security forces in several parts of the country. The British-based Syrian Observatory for Human Rights said seven of the deaths occurred in Hama when security forces fired on opposition protesters who infiltrated a pro-government rally.
Syria's call for an Arab summit on the political unrest was seen as another possible bid by President Bashar al-Assad to buy time as he faces punitive action over a crackdown that the U.N. estimates has killed more than 3,500 people since mid-March.
In a thinly veiled warning, the government said it was calling for the meeting "because the fallout from the Syrian crisis could harm regional security" - an apparent effort to play on fears that Assad's ouster would spread chaos around the region.
But in a significant concession, Syria invited Arab League officials to visit before the membership suspension is scheduled to take effect Wednesday and said they could bring any civilian or military observers they deem appropriate to oversee implementation of an Arab League plan.
The Syrian government is usually loath to accept anything resembling foreign intervention, and the invitation signaled the government's alarm over the Arab action.
Arab League officials did not immediately respond to the request for an emergency summit. Secretary-General Nabil Elaraby, on a visit to Libya, demanded immediate implementation of the Nov. 2 peace plan, which calls on Syria to halt attacks on protesters, pull tanks out of cities, and hold talks with the opposition. Syria signed on to the plan, but nothing has changed on the ground.
In voting for the suspension, the Arab League said it would meet again Wednesday in Morocco to reconsider the decision, giving Assad some time to try to prevent it.
Arab nations are eager to avoid seeing another leader toppled violently, as Libya's Moammar Gadhafi was.
Assad asserts that extremists pushing a foreign agenda to destabilize Syria are behind the unrest, rather than true reform-seekers aiming to open the country's autocratic political system. Sunday's demonstrators accused Arab countries of being complicit in the purported conspiracy.
Iraq, which abstained from Saturday's vote, warned that the Arab League suspension could make matters worse.
"The suspension . . . will deprive the Arab League of any communication channel with the Syrian government, and this move does not serve the interests of the Syrian people," Iraqi government spokesman Ali al-Dabbagh said.
Members of the Syrian opposition, meanwhile, rejoiced. "We consider this decision to be a victory," said Bassma Kodmani, a spokeswoman for the Syrian National Council, an opposition umbrella group.