Sunday's vote, dismissed by Kiev as illegal, has triggered the worst East-West crisis since the Cold War, and ratcheted up tensions not only in Crimea but also eastern Ukraine, where two people were killed in clashes late on Friday.
The streets of the Crimean capital of Simferopol were calm on Saturday, despite a heavy military presence incongruous with the normally sleepy town, Reuters reported.
Crimean Prime Minister Sergei Aksyonov, whose election in a closed session of the regional parliament is not recognized by Kiev, said there were enough security personnel to ensure that Sunday's vote would be safe.
"I think we have enough people - more than 10,000 in the self-defense (forces), more than 5,000 in different units of the Interior Ministry and the security services of the Crimean Republic," he told reporters.
In Kiev, the Ukrainian parliament voted to dissolve the Crimean regional assembly which has organized the referendum and backs union with Russia.
One Ukrainian nationalist leader in the Kiev legislature said the Crimean assembly must be sanctioned to discourage separatist movements in the mainly Russian-speaking east of Ukraine.
Aksyonov and Moscow do not officially recognize that Russian troops have taken control of Crimea, and say that thousands of unidentified armed men visible across the region belong to "self-defense" groups created to ensure stability.
But the Russian military has done little to hide the arrival of thousands of soldiers, along with trucks, armored personnel carriers and artillery. Masked gunmen surrounding Ukrainian military installations in Crimea have identified themselves as Russian troops.
Moscow leases the Crimean port of Sevastopol from Kiev to station its Black Sea Fleet. Under the deal it can station up to 25,000 troops there but not on other Ukrainian territory.