Relationship of grain size distribution of artificial spawning grounds and survival of eggs of white�]spotted charr (Salvelinus leucomaenis) was examined. Rates of very fine particles finer than 0.074mm in three artificial spawning grounds were 0.8�|1.4% by weight. The rates were much higher than those of stream beds in general mountain streams. It was feared that the extremely high rates of the very fine materials would prevent stream water with oxygen from reaching at laid eggs and cause low survival rate. The rate of eyed eggs was 90.0% for the laid eggs, and the rate was higher than those of other artificial spawning channels. Therefore, the high rates of very fine particles did not damage the eggs in this case. However, the results should not be generalized but a reference for the development of the artificial spawning ground technology.

Key words�Fartificial spawning ground, grain size, survival, laid egg, white�]spotted charr