Man has always been in pursuit of energy to meet his ever increasing demand. The conventional power generation techniques cause environmental problems. Also there is a growing need to generate power from renewable resources. In this project we are designing and fabricating a machine which generates power using buoyancy and gravity. This machine utilizes the upward force exerted on an immersed body by supporting fluid medium. It also uses the downward motion of the body due to its own weight. These two forces on either side make the system unstable and can be used to rotate a shaft for generating power efficiently. The buoyancy and gravity are the sources of energy so it can be used all over the earth. It would not make any environmental problems. This machine can work entire day and can generate power which will be enough to satisfy the needs. Also this power generating unit is flexible to use in industries and households by converting the output into any useful energy form.