In this paper I have identified Koguryŏ's stars which appear in the Murals of Kakchŏ and Muyong(early 5th cen. A.D.), both located in Jian, the capital of Ancient Koguryŏ. They have seven or eight constellations impressively drawn on the ceiling of the main chambers which are octagonal arch-shaped domes. The stars are represented by large round red spots(Kakchŏ Mural) or yellow spots(Muyong Mural) which are interconnected with three parallel black lines. The constellations of Koguryŏ murals are drawn uniquely in a system of four directional constellations, which also appears in the two murals. This system consists of the three stars of the Northern Dipper located in the north and the Six Stars of the Southern Dipper(the Archer) in the south. The Double Three Stars in the east are located above the Sun-disk and those in the west are above the Moon-disk. The Eastern Double Three Stars are identified as the Sim-su(α, σ, τ Sco) and the Pang-su(β, δ, π, ρ Sco) which correspond to the heart and head of the Scorpion, respectively. The Western Double Three Stars are the Sam-su(ζ, ε, δ, α, γ, κ, β Ori) and the Pul-sŏng(42, θ2, ι Ori) corresponding to the Great Hunter. The Northern Three Stars under the Big Dipper has been identified as the Koguryŏ's northern polar constellation. In China this appears as the Northern Five Stars. The two Single Stars in the Kakchŏ Mural, one on the summit of the ceiling is identified as the Po-sŏng(80 UMa, Alcor), and the another, at the end of Big Dipper, as the Ch'oyo-sŏng(γ Boo) or the P'il-sŏng(exact position unknown). Lastly, the Single Star in the Muyong Mural is identified as the Ch'oyo-sŏng or the Po-sŏng.