Abstract: Full ocean depth buoyancy materials were prepared with glycidyl ether type epoxy resin, aromatic polyamine hardener and hollow glass bubbles. Here were investigated the influences of the volume fraction of hollow glass bubbles K1 on such performances as density, compressive strength, resistance to hydrostatic pressure and water absorption rate. The results showed that when the total volume fraction of the hollow glass bubbles in the full ocean depth buoyancy material was 66.7%, the introduction of appropriate amount of hollow glass bubbles K1 instead of HM42 could reduce the density of full ocean depth buoyancy material, the compressive strength was not less than 132 MPa, the resistance to hydrostatic pressure was not less than 150 MPa, and the water absorption rate was not higher than 0.2%. It's prospective to meet the safe usage of full ocean depth equipments.