Islamic Revolution
Carrying images of Islamic republic founder Ayatollah Ruhollah Khomeini and Supreme Leader Ayatollah Ali Khamenei, demonstrators supporting the government re-affirmed their allegiance to the Islamic Revolution.
Demonstrators also chanted anti-US and anti-Israel slogans during the rallies.
High-ranking Iranian officials also attended the rallies.
The Islamic Republic President Hassan Rouhani and Louis Farrakhan, leader of the US-based Islamic religious movement Nation of Islam are scheduled to make speech in the ceremony in Tehran.
Some 5200 journalists including 280 foreign reporters and journalists are covering the rallies.