The group have said they aimed to 'listen and talk' to Cubans
Raul Castro has held talks with members of Congress in his first face-to-face meeting with US politicians since he became president last year.
State television showed Mr Castro talking to members of the delegation, which is in Havana to explore ways of improving US-Cuban relations.
No details of what was said in their discussions were released.
Barack Obama is expected to ease some of the travel and economic restrictions imposed on Cuba nearly 50 years ago.
Barbara Lee, the leader of the seven-strong group of Democrats, said the group did not carry a message from President Barack Obama but had come only to "listen and talk" with the Cubans.
Last week, a bipartisan group of US senators introduced a bill that would allow all US citizens to travel freely to Cuba for the first time since 1962.
Democratic Senator Byron Dorgan said the policy had "failed for 50 years", adding that he believed it would win enough votes in the US Congress to pass.
But Republican Mel Martinez said the US should support pro-democracy activists, not "the Castro regime".
At present, the US only allows its citizens to go to Cuba if they are journalists, government officials or on a humanitarian mission. Students or people wanting to visit close relatives can also apply for special licences.
The US began imposing restrictions on Cuba after Fidel Castro took power in 1959, making it the only Communist state in the Americas - and a Cold War flashpoint.
His younger brother, Raul, formally took over the presidency from him in February last year.