"In my 40 years of political life, I have had no such claims to change the regime," Erdogan said in an interview aired live on state-broadcaster TRT, according to Anadolu Agency.
He said the debates on regime change in the country ended in 1923, when Mustafa Kemal Ataturk established modern Turkey as a republic.
"But this [government] system is not responding to [current] needs," Erdogan said.
Turkey's main opposition Republican People's Party (CHP) has claimed during its 'No' campaign that the constitutional change would lead to a regime change.
Erdogan said that almost all polls predicted a 'Yes' victory.
"Some predict the rate to be below 55 percent while others say it is likely to be between 55-60 percent," he said.
Sunday’s referendum in Turkey addresses a host of constitutional reforms that would hand wide-ranging executive powers to the president.
The post of prime minister would be abolished and the president would also be allowed to retain ties to a political party.
Other changes include the minimum age of parliamentary candidates reduced to 18 and the number of deputies increased to 600.
Also, simultaneous parliamentary and presidential elections for a five-year term would be held in November 2019 under the new Constitution.