FACTBOX: Facts about Cuba's Communist party

(Reuters) - Fidel Castro retired as Cuba's head of state this week after 49 years in power, but he retains a powerful position at the head of the ruling Communist Party.

Here are some facts about the party:

* The Cuban Communist Party (PCC) has 820,000 card-carrying members, out of a total population of 11 million on the island. The party was founded in 1965, merging various revolutionary groups under Castro's leadership. All other political parties were banned.

* All top level government and military officials are party members, as are most lower-level functionaries, and leaders of labor and other mass organizations. The Cuban Constitution adopted in 1976 states that the PCC is the "highest directing force" of the Cuban state and society.

* Fidel Castro has held the post of first secretary and Raul Castro has been second secretary since the party's founding.

* A party congress is held every five years to elect the Central Committee -- currently 134 members -- and set general policy guidelines. However, the last congress was held more than 10 years ago in 1997. Party insiders say a congress may take place during the next 12 months.

* The Central Committee elects from its members a 25-member Political Bureau responsible for day-to-day decisions, and a 12-member secretariat that carries out those decisions.

* The party's youth organization, the Union of Young Communists, has around 600,000 members.

(Reporting by Marc Frank in Havana, Editing by Michael Christie and Frances Kerry)