There are altogether 16,559,254 eligible voters, according to the Central Election Commission (CEC).
Chang Cheng-hsiung, CEC chairman, estimated the turnout at 6.7 percent yesterday.
At least 11.38 million people would vote for 225 members of the parliament, if the prediction were borne out.
A total of 16,258,979 eligible voters can elect 168 candidates to fill "regional" seats. They will be elected from 31 constituencies across the country.
Another 300,275 will elect eight aborigines from among 18 candidates.
Eight of the remaining 49 seats are reserved for overseas Chinese candidates.
The other 41 will be distributed among political parties as their lawmakers at large on a proportional representation basis.
Running for the regional seats are 386 candidates, of whom 92 were Democratic Progressive Party nominees. The Kuomintang has nominated 74 candidates, the People First Party 41, and the Taiwan Solidarity Union 30.
Other parties fielding candidates include the Non-Partison Solidarity Union with 25, the Taiwan Independence Union with four, and the New Party, the Hui Hsin Volunteers and the Industrial Education League with one each.
One hundred and sixteen independents are also running.
The ruling party has named six candidates for overseas Chinese seats, followed by the Kuomintang and the People First Party with five each. The Taiwan Solidarity Union and the Non-Partison Solidarity Union have nominated one each.
For at-large seats, the Kuomintang has recommended 24 candidates, the Democratic Progressive Party 31, the Taiwan Solidarity Union 10, and the People First Party nine.
Across the country 13,930 polling stations have been set up. Altogether 162,782 workers will man them.
They will open at 9 a.m. and close at 4 p.m.
Tabulation of votes will start as soon as the stations are closed.
The results of the elections will be known by 9 p.m., the CEC chairman said.
Asked if the voting will be suspended if a bomb attack occurs, Chang said it will go on, if only one or two polling stations are affected.