"A group of our best lions launched a new attack on some dens ... After casing the targets, some hotels were chosen which the Jordanian despot turned into a backyard for the enemies of the faith, the Jews and Crusaders," the statement on a website usually used by the group, said.
"Let the tyrant of Amman know that his protection ...for the Jews has become a target for the mujahideen and their attacks, and let him expect the worst," it added.
Jordan is one of two Arab countries that have signed a peace treaty with Israel. It is also a close US ally in the region.
The statement, which could not be immediately verified, was signed by al-Qaida's spokesman in Iraq.
It said Iraq's al-Qaida, led by Jordanian Abu Musab al-Zarqawi, would later give more details about the attacks, but did not say if they were carried out by bombers.
The blasts ripped through three international hotels in Amman on Wednesday night, killing at least 57 people and wounding 110. Officials have blamed al-Qaida.
In August, Iraq's al-Qaida also claimed a failed rocket attack on US Navy ships in Jordan's Aqaba port.
Al-Zarqawi, whose group is waging a battle against US and foreign forces in Iraq, has vowed to punish Jordan's rulers for aiding the United States and Israel.
Al-Zarqawi, dedicated to overthrowing the Jordanian monarchy and establishing an Islamic state was jailed in Jordan for 15 years in 1996. He was freed three years later under an amnesty by King Abdullah.