In his lifetime Kim Jong Il regarded it as his lifelong duty to creditably serve Kim Il Sung. His whole life was consistent with the efforts to accomplish the revolutionary cause of Juche pioneered by the President.

He formulated the Juche idea, founded by the President, as Kimilsungism and declared it a program of the Workers' Party of Korea to dye whole society with the idea.

From the 1990's to the early 21st century, a large number of organizations for the study of Kim Jong ll's works emerged throughout the world with his august name. This was the world public's recognition of his feats performed in further developing the revolutionary idea guiding the era of independence.

The leader saw to it that the Tower of the Juche Idea was erected in Pyongyang.

In order to evolve the Juche idea to suit the developing situation, he authored many works, including "On the Juche Idea", "On Some Problems of Education in the Juche Idea" and "Let Us March Forward Dynamically along the Road of Socialism and Communism under the Unfurled Banner of the Anti-imperialist Struggle".

And, on the basis of the Juche idea, he put forward the Songun idea calling for giving priority to military affairs.

The ideas and theories he advanced in his lifetime serve as a treasure for the Korean people.