Abstarct: In building construction , a growing demand exist for open floor spaces(i.e.,using less column and less wall partitions). At the same time, more light weight structural materials with increased strength are available. Using these new materials with open floor spaces induces excessive vibrations due to human activities (walking , aerobics, etc.). In these research ,vibration control of non industrial composite floors due to human activities is discussed. One control method for reduction floor vibrations is baxsed on tuned mass dampers(TMD). In these research at first mathematical theory for multi degree of freedom floor systems equipped with TMD is presented. Next, optimum design parameters are presented in the form of appropriate equations and graphs. For modeling of TMD and composite floors, SAP2000 finite element program is utilized and modal and time history dynamic analysis is performed and key technics of modeling have been presented. Performance of TMD is evaluated by numerical simulations of a footbridge and an electronic office ( an office mainly baxsed on computers rather than traditional filling systems). Results implicate that more than fifty percent reduction at floor peak acceleration is achieved by using TMD. In another example, application of TMD for vibration reduction in floors of a multi-story sport and wrestling complex is studied. Results indicate that while TMD can reduce the vibrations but the cost is a concern. Accordingly,TMD can be used for improvement of the existing floors.