Napoli will pay the goalkeeper €4 million (£3.4m) in wages, and Reina will join the club on their pre-season training camp in Trentino, Northern Italy, for his medical.
Sky Sports News Italia claims Napoli will have an option to but Reina permanently for €10m (£8.6m).
Napoli are also close to signing strikers Leandro Damiao and Gonzalo Higuain following the £55m sale of Edinson Cavani to Paris Saint-Germain.
It’s reported Napoli have a deal with Liverpool for Pepe Reina after Julio Cesar’s agent explained he “won’t take a pay cut.”
Julio Cesar's agent Josias Cardoso told Radio CRC the reasons for the breakdown of his move to Napoli, saying: "Their proposal was too far away from what he currently earns at QPR and we already did them a favour by not asking for a raise.
“We are talking about a goalkeeper who has returned to the level he was at when winning the Treble with Inter. He doesn’t want to take a pay cut, as he could easily have demanded an increase and did not do that.”