Castro said Carter was welcome to meet anyone in Cuba
Mr Carter is due to make a live televised address to the Cuban people on Tuesday and will meet with religious and human rights groups on Thursday, before leaving Cuba on Friday.
Earlier a smiling Mr Castro met Mr Carter as he arrived in Cuba, the pair then walked - along with Mr Carter's wife Rosalynn - to a podium while they stood as both countries' national anthems were played, a rare occurrence in communist Cuba.
'Common points'
In his welcome speech Mr Castro had said that the former US president was welcome to meet with anyone in Cuba "even if they do not share our endeavours" - a reference to the human rights activists Mr Carter is expected to meet.
He also praised his guest for his efforts over the years to normalise relations between Cuba and the US.
"It is no secret that for almost a century there have not been optimal relations between our two states," he said.
"However, in the four years as president you had the courage to make efforts to change the course of those relations."
Mr Carter added that the importance of the visit was to establish a form of dialogue between the two countries.
"We realise that we have differences on some of these issues, but we are grateful for the chance to try to identify some common points."
Access to sites
Mr Castro has also offered former US President Jimmy Carter "free and complete access" to personally inspect scientific research centres.
The invitation comes in response to last week's accusations from the US Government that Cuba was producing biological weapons.
After he left office in 1981, Mr Carter set up an organisation designed to advance peace and understanding around the world.
On 6 May the US Under Secretary of State, John Bolton, placed Cuba firmly in what Washington calls its axis of evil, accusing Cuba of trying to develop biological weapons.
Five days later President Castro responded live on Cuban television, calling Mr Bolton a liar and challenging the US to provide some proof to support its allegations.