He was receipted at Khartoum International Airport by Sudanese vice-president, Faisal Hassan Abrahim and a host of government officials.
He will meet his Sudanese counterpart Omar al-Bashir for talks ahead of the peace signing ceremony.
The representatives of 14 armed groups are set to sign later on Tuesday a preliminary peace agreement in the presence of Bashir, Touadera and officials of the African Union which brokered the Khartoum talks last month to bring lasting peace to the CAR, rocked by political violence since 2013.
The CAR government and the militias had tentatively reached a deal last weekend to end all hostilities.
The negotiations, which had focused on power-sharing and a transitional arrangement backed by the AU, began in Khartoum on January 24.
According to United Nations figures, at least tens of thousands have died and some one million have been forced to flee their homes in the course of the CAR conflict.