Koguryo, which attached importance to astronomy from the early period of its existence, made an astronomical chart carved on a about 2m-long and about 1.2m-wide stone plate in the late 5th century to early 6th century on the basis of rich data about solar and lunar eclipses, movement of meteor and comet and even sunspots.

The chart showed 1 467 stars, which were visible in the night sky of the then capital Pyongyang, in 282 constellation divisions in a circle. The basic data needed for astronomical observation were clearly presented.

A rubbed copy of an astronomical chart that had been thought to have been lost was discovered in the early days of the feudal Korea dynasty (1392-1910).

The stone chart, a little modified to suit the astronomical situation of the late 14th century, was very scientific and meticulous at that time, and therefore became a very precious astronomical document for quickly locating the stars for rapid and accurate astronomical observation. This indicates that by the end of the 14th century the astronomical observation of our country became in-depth.

The stone chart has been known to the world from long ago for its accuracy and richness and is one of the precious cultural heritages, a reminder of the level of the development of the astronomy of our country in the Middle Ages.