This paper proposes a decentralized vibration control method for cable-network structures in space antennas, which are large and so flexible structures and show non-linear behaviors. The main advantage of this method is that it is possible to gain adaptability to changes of models, such as size or depth changes of parabolas that come from diversity of space mission and manufacturing errors. The control method is decentralized direct velocity and displacement feedback (DVDFB). Force Density Method (FDM) is used for structural analysis of cable-network structures. The index “Force Density (FD),” which shows tension condition of each cable, can be used for decision of the placement of sensors and actuators. The results show that, even though non-linear behaviors such as large displacement and slack of cables are occurred, vibration control of this structure system is possible. And then, it is also shown that the shape-changed model can obtain the control effect by this method.