The march began at 2.30pm. The PDRC announced it planned to conduct a ceremony to extend best wishes and loyalty to His Majesty the King on the occasion of the Coronation Day, and to pray for success in their planned decisive rally against the government.
The PDRC, led by many former Democrat MPs, is demanding the resignation of the caretaker Yingluck Shinawatra government and national reform before elections.
It accuses the Yingluck government of having seriously violated many laws and of being plagued with corruption.
Some heads of villages and village groups joined the PDRC march. Most demonstrators were wearing yellow.
The anti-government protesters marched along Rama IV Road and via Yaowarat, the Ministry of Defence and the City Pillar before reaching Sanam Luang.
In northern Tak province about 100 yellow-clad PDRC members rallied at a shrine of King Naresuan the Great on the Asian Highway opposite the Mae Sot municipal office on Monday.
They worshipped King Naresuan and prayed for success for the PDRC movement, expressed their loyalty to the royal institution and demanded political reform before elections.