Records regarding to magnetism in the written Korean history were surveyed. In this article, we depicted how the magnetism (magnet) was understood by the public in the past in the Korea. The records about magnetism could be chronically categorized into three eras; 1) an era of recognizing a magnetic characteristics, 2) era of recognizing a magnetic pole, and 3) era of acquiring a modern knowledge. The written history of the Silla dynasty (BC57-AD935) revealed that a magnet was produced in this era. However, no record about magnet was found in the written history of the Goryo dynasty (918-1392). It was revealed that throughout the Korean history the interest in the magnetism (magnet) was emphasized most in the Josun dynasty (1392-1910). The magnetism (magnet) was most widely exploited in a geomancy. A magnetic compass was used widely to find a merciful direction and place in everyday life. In the era of Josun dynasty, a magnet was exploited as a magnetic compass for a navigation over the sea. An interesting usage of the magnet in the Josun dynasty was found in the pharmaceutical purpose.