Abhisit announced the decision in parliament after a late-night debate on violent anti-government street protests and told reporters later that the emergency would formally be lifted at midday (0500 GMT).
"The lifting of the decree will send a signal to the world that Thailand is back to normal," he said.
Emergency rule was imposed in the capital and surrounding areas 12 days ago to quell violent street protests involving thousands of demonstrators intent on toppling the government.
Two people were killed and more than 100 injured in the worst street violence in 16 years, threatening further damage to the key tourist industry and Thailand's recession-bound economy.
Bookings taken by Thai Airways International, the state-controlled airline, have fallen by 20 percent – mainly from other Asian countries – since the state of emergency was imposed, the Nation newspaper reported.
Speaking at the end of the two-day parliamentary debate, Abhisit said lifting emergency rule would "show that we are sincere about wanting reconciliation".
He said an independent commission would investigate the violence in Bangkok and the resort town of Pattaya, where the government was forced to cancel a summit of Asian leaders after demonstrators invaded the venue.
Supporters of exiled former Prime Minister Thaksin Shinawatra, who ended their three-week old street campaign after security forces moved in to restore order, have accused Abhisit of using heavy-handed tactics against them.
Three top leaders of the red-shirted movement have been arrested and police are hunting for others.
The emergency measures barely affected daily life in the city of over 10 million people. Abhisit said protests could resume as long as they were peaceful.
The pro-Thaksin United Front for Democracy against Dictatorship (UDD) wants Abhisit to resign and call new elections, arguing that his victory in a parliamentary vote in December was illegitimate.
Abhisit, who has previously rejected a new poll, proposed a new commission to study amendments to the 2007 constitution, which was drafted by a military-installed government after Thaksin was removed in a coup a year earlier.
Critics have said the constitution was a step back from the 1997 "People's Charter", which allowed for a fully elected upper house.
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