Title for thesis: 'Differential geometric and symplectic interpretations of stability in the sense of Gieseker'. Abstract for Thesis: For holomorphic vector bundles over compact Kahler manifold, stability in geometric invariant theory can be understood in differential geometric way. This completes the previous works along this direction by Donaldson, Uhlenbeck and Yau. It gives naturally a new system of Monge- Ampere equations closely related to the Atiyah Singer Index theorem. From the symplectic point of view, a one parameter family of gauge invariant symplectic form on the space of connection is introduced and the limiting symplectic reduction can be interpreted as the moduli space in the sense geometric invariant theory. A natural lagrangian using Bott-Chern form is also constructed which generalized Donaldson lagrangian.