Study on the egg envelope of an endemic Korean freshwater fish, Coreoleuciscus splendidus was carried out by light and scanning electron microscopes during its spawning season. The egg envelope on the entire egg is filled with plenty of long cylinder-like villi before and after fertilization. The fertilized eggs consist of two regions, the attaching and non-attaching parts to stick to the substrates. The villi covering the fertilized eggs have three kinds of villi in its length: 1) normal- sized villi of an average of $10.6{mu}m$ on the non-attachment part; 2) longer and more slender villi over about $20{mu}m$ on the attachment part, at least being two times longer than those of the non-attachment; and 3) shorter villi under about $5.0{mu}m$ around the micropyle, with half the size of the non-attachment villi. The micropyle rotated in a counter-clockwise direction with five pieces of the ridges.