The rally was planned for September 3 on Moscow's Lubyanka Square, but rights activists said authorities told them no rallies to mark the anniversary would be authorized in Moscow.
Svetlana Gannushkina, the leader of the rights group Civic Assistance, told RFE/RL that she believes the authorities did not sanction the rally to avoid drawing the public's attention to what she describes at the official investigation's failure to reach "objective conclusions."
"The authorities are not interested in letting people speak a lot and speak loudly about Beslan now," she said.
More than 330 people, many of them children, died when security forces stormed the school seized by militants on September 1, 2004.