Local authorities in the eastern region are expected to pass laws giving them greater power over the province's finances and security operations if the referendum is passed.
 
Evo Morales, the president, has not followed through with a threat to bring troops into the region, but violence between his supporters and those backing autonomy is feared.
 
A rally was held in the city of Santa Cruz by 5,000 indigenous Indians on Friday in protest at the referendum seeking greater independence.
 
Political reaction
 
The referendum is considered to be a reaction to Morales's efforts to change the constitution to provide increased power and wealth to Bolivia's indigenous population.
 
He  has said that he will ignore the result of the vote, calling the move unconstitutional and separatist.

Morales said on Friday that the dispute should be decided by a nationwide referendum.

However, he said some of the state's demands may be worked into Bolivia's new constitution if the referendum is approved.
 
"If we politicians can't find a way to agree, let the people decide with their vote," he said.
 
Leaders in Santa Cruz want greater autonomy in order to keep more of the province's natural gas revenues and to protect their large plantations and ranches from Morales' plan for land redistribution.
 
Morales has said that he needs a strong central government to distribute Santa Cruz's wealth to the rest of the country.
 
In a related event, the Organisation of American States said on Friday that it supported Bolivia's territorial integrity.
 
A resolution was passed by the group rejecting "any attempts to disrupt" the country's constitutional order and its territorial integrity.
 
It also appealed to those involved in the political process "to avoid any action to could undermine peace, constitutional order and peaceful coexistence among Bolivians".