The gypsum bonded particleboard is a new kind of building material. The object of this paper is to study the possibility of making gypsum particleboard with cotton stalk using the semi-dry method.The results show that although the cold water extractive of cotton stalk retards the setting of gypsum, the setting characteristic of gypsum is changeable and can also be controlled by adding certain chemical accelerator or retarder. The influences of some production parameters were also investigated on the properties of the board.The main production parameters would be suggested:1. Density of the board: <1.2 g/cm~3.2. The ratio of cotton stalk and gypsum: <0.25 (by weight).3. The ratio of water and gypsum: 0.40 (by weight).