In the present paper,the construction and working principle of stone-mill-shaped sievesand elutriation separator for benthos survey are introduced. The stone-mill-shaped sieves are composed of three round screens and a mildde frame.The lowest screen is the biggest in diameter.Compared with the existing square sieves,thestone-mill-shaped sieves have the advantages of preventing losing organisms when sample In the present paper, the construction and working principle of stone-mill-shaped sievesand elutriation separator for benthos survey are presented. The stone-mill-shaped sieves are composed of three round screens and a mildde frame. The lowest screen is the biggest in diameter.Compared with the existing square sieves, thestone-mill-shaped sieves have the advantages of preventing losing organisms when sample