Abstract: Most of the large or medium sized ordinary biogas digesters, in the world, have the shapes of the cylinder, the spindle and the egg. As to save the constructioncost, the digesters to be designed in China are the shape of rectangle. By author's studying the shape of the digester, in first place, should be disigned to agree the requirements of the fermentation technology. Then, the designers may consider the case of construction and low construction cost. Author wishes to suggest to use the spindle-shaped digester in China which will be comparatively comformed to the Chinese conditions. The structure dimensions of the spindle-shaped digester are as follows: the angle of the top pyramid of the digester is 120 degrees, the body is in cylinderical shape and the angle of the bottom pyramid is 90 degrees. Author proposed a whole set of formulae to calculate the dimensions of the digester when the capacity is given. Moreover, the surface area of the digester will be the smallest. Such spindleshaped digester requires the capacity more than 200 m³.