The Dunhuang Grottoes is not only a Buddhist art famous treasure house in the world, but also a museum of various pigment specimens. More than thirty types of pigments have been found. Some of them, such as lapis lazuli, litharge, crimson vitriol, mica powder, gold powder, silver powder, aerogun, orpiment, railcar, gypsum, etc., were used in the early time but there were not recorded. The application of the above pigments indicates that ancient China had a great achievement in chemical technology. A huge amount of pigments used in the past indicates that minerals and plants pigments were applied integrally an ancient time and also reflects the well development of pigment chemistry and the related metallurgic technology at the time. Ancient people through the analytical methods obtained some information such as: chemical and physical properties of pigments, color fading, color change and other problems of pigments, and aging of binding media. The information has been applied to color change prevention and cultural relics conservation. The research on pigment sources revealed some facts about the exchanges of cultures, trades, and techniques between the East and the West at ancient time. The rich, splendid, and colorful mural paintings at Dunhuang provide variety of pigment samples from polychromy arts at different dynasties. Studying the compositions, applications, and production techniques of ancient pigments are very important for cultural relics conservation practice and research. Based on the international studies on the pigments used at the Mogao Grottoes, more than thirty types of pigments have been found. Vermilion or cinnabar, red lead, ochre, red vitriol, reagan, orpiment, litharge, gold powder, gold foil, malachite, atacamite, azurite, lapis lazuli, ultramarine, lead powder, gypsum, chalk, mica, lead dioxide based on the historical records and current scientific research, more than ten major mineral pigments were found and they were either manufactured locally through very complicated physical process, or transported semi or final products from central China; or imported from far away ancient Western world.