Some of the defendants told the opening session of their trial in Jordan's military court that they believed jihad "isn't a crime".
Standing in the dock to enter their pleas, they accused the Jordanian government of being an "infidel" and a "puppet" of the US.
The 17, all in custody, are charged with different counts, including conspiring to commit terrorism and attempting to harm Jordan's relations with a foreign country - a reference to Iraq, where the suspects allegedly planned to carry out operations against US forces, but did not manage to travel there.
If convicted, they face up to 15 years in jail.
One of the 17, a Jordanian of Palestinian origin identified as Loai Abu-Nameh, is said to have known an unnamed Syria-based contact of Abu Musab al-Zarqawi, the Jordanian-born leader of al-Qaida in Iraq, according to the prosecution's indictment.
The indictment said none of the other defendants were believed to have a direct link to al-Zarqawi or other known organisations.
One of the men allegedly had
links to Abu Musab al-Zarqawi
The plot was uncovered and foiled when the men - aged between 22 and 36 - were arrested in different police sweeps across Jordan in July, the indictment said.
The government announced the arrests last month, but did not reveal details of the plot.
In Jordan, the men allegedly planned to strike Jordanian anti-terrorism officials and US military personnel involved in training Iraqi army and police recruits, the indictment said.
It said the group surveyed its targets and sought to purchase arms locally.
The indictment gave few other details on the plot said to have been hatched in Jordan earlier this year by alleged prime suspect Mutasem Suleiman, who, like many in his group, is a Jordanian of Palestinian origin.
There is also a Syrian in the cell.