Ceremonial head of state Kim Yong Nam on Thursday told a sea of people in the main plaza in Pyongyang that Kim Jong Un inherits his father's "ideology, character and revolutionary" cause.
Kim Jong Un looked on with his head bowed from a balcony during the memorial.
He was flanked by the top party and military officials.
The memorial began with a silent tribute for Kim Jong Il. The elder Kim led his 24 million people with absolute rule after taking power following the 1994 death of his father, North Korea founder Kim Il Sung.