The anti-government protesters will move in an eight-kilometre loop starting from Democracy Monument to the Memorial Bridge, Phahurat, Yaowarat, Worachak and back to their main Ratchadamnoen base.
The route could be adjusted, the group added.
PDRC spokesman Ekanat Promphan said the rally would start at 10am and would be held only in daylight hours because of safety concerns.
The anti-government group plans more marches on Tuesday and Thursday but the routes have not been disclosed.
Leader Suthep Thaugsuban has said the PDRC intended to use street rallies this week to build momentum to attract as many people as possible to its main demonstration a week from Monday.
He has promised that the Jan 13 event would be the "last battle" to unseat caretaker Prime Minister Yingluck Shinawatra and her cabinet.
Mr Suthep has used the expression "last battle" on numerous other occasions since he began the campaign in early November.
In an indication that the campaign could yet be prolonged, he said the shutdown would continue until the PDRC's demands are met and obstacles to reform are lifted.