NOVELTY - The apparatus has float members (26) placed within tubular members (12) and adapted for containing gas and liquid. An introducing and discharging unit is used for introducing and discharging gas and liquid into and from the float members. A turbine generator comprises a rotating unit to rotate for producing power. Constant ascending and descending of the float members in coordinated alternating relation within the tubular members force the liquid flowing through a conduit of each tubular member to act forcibly upon the rotating unit to rotate the turbine generator to produce power.    USE - Apparatus for producing hydroelectric power with use of a hydroelectric turbine generator.    ADVANTAGE - The apparatus realizes hydroelectric power production in an improved manner. The apparatus improves production of hydroelectric power by utilizing the injection of controlled highly pressurized water into a turbine to power a generator. The apparatus improves production of hydroelectric power utilizing the combined application of the principles of buoyancy and gravity, and is easy to install, operate and maintain. The apparatus improves production of hydroelectric power that utilizes multiple water filled tubular structures with closed cylinders inside each tubular structure containing ether gas. The close distance between an exterior wall of the float member and an interior sidewall of the tubular member serves to seal the two adjacent areas and pressure build up of water flows in the ascending float member, so that a 0-ring gasket improves the sealing effect and increases the pressure and overall buoyancy effect.    DETAILED DESCRIPTION - The apparatus includes power-assisted unit derives from an energy source from a group comprising solar energy, hydroelectric energy, wind turbine energy, nuclear energy and geothermal energy.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross section elevational view of a single tube apparatus.    Tank compartment (9)    Tubular members (12)    Support members (24,)    Float members (26)    Brake units (32-38)