Top election official Jose Luis Exeni said on Monday the president's decree, which would have seen more land being transferred to the country's indigenous population, said the referendum was unlawful.
"The running Constitution says the decision on such a referendum should be made by the National Congress [legislature], not the president," Exeni said.
A draft constitution approved last year, but boycotted by the right-wing opposition, is designed to improve the living standards and rights of most of the country's impoverished indigenous majority in eastern Bolivia, according to Morales.
Around 4 million people took part in a referendum on August 10 on whether left-wing nationalist Morales, the country's first indigenous president, and his administration should remain in office.
The referendum was called as a result of the president's opposition to greater autonomy for at least five Bolivian provinces that account for the bulk of the country's natural gas reserves, 80% of its GDP, and where two thirds of the population lives.
Morales received the backing of 67% of voters in August, with five out of the eight right-wing governors retaining their posts.
Morales, currently on a visit to Iran, has conducted a large-scale campaign for the nationalization of various sectors of the economy over the past year. The government took control in May of the production, refining and transportation of oil and gas.
Presidential opponents suspect Morales of trying to use the new constitution to retain power
permanently.
