In a dawn ceremony, the leftist leader extended his arms to receive the first rays of the morning sun before breathing in the incense from a large pyre lit to bring good fortune.
The ritual, set to the sounds of Andean music, was held at the archaeological site of Tiahuanaco (or Tiwanaku) in western Bolivia, a collection of stone ruins thought to have been a spiritual and political center from AD 400 to 900.
Morales took office on January 22, 2006, after defying centuries of discrimination against Bolivia's indigenous communities to win a landslide election victory.
He has since presided over a period of robust economic growth and transformative changes for the long-suffering indigenous majority.
A former coca grower who got his start in politics as a union leader, he has deftly managed the resource-rich economy, which has more than tripled in size during his decade in office.
But Morales, who is already the longest-serving president in Bolivian history, is increasingly accused of trying to cling to the presidency for as long as he can.
Three years ago, Bolivia's Supreme Court cleared the way for him to serve a third term when it ruled that his first term was exempt from a new constitution adopted in 2009 that imposed a limit of one reelection for sitting presidents.
Morales will officially mark the anniversary tomorrow with a ceremony in Congress, where he will deliver a nationally televised address.
