This Study aims to perform a methodology study and design method for nanofluid dampers. The development of nanofluid dampers comprises three parts, such as material properties, damper behaviors, and engineering applications, in brief. In the first part, 90 nanofluid samples are fabricated with various combinations of different types of fumed silica particles, PPGs, and fluid concentrations. The viscous curves and fluid curves of nanofluids are obtained from rheology tests and also simulated by a triple-Cross model with eleven parameters. Through observing from the results, it could be summarized that the initial viscosity and maximum viscosity are proportional to the fluid concentrations and the polymer chain lengths, but the shear rates corresponding to the maximum viscosities are... inversely proportional to these two variations; in addition, the shear thickening and shear thinning effects become more obvious when the concentrations of fluid riseThe second part aims to apply the fluid properties into damper devices by means of theoretical derivations and full-scale damper performance tests. First, an exact solution for the force curves of nanofluid dampers is deduced based on the viscous curve of the fluid triple-Cross model and the theory of equilibrium of fluid momentum. However, owing to the complex viscous model of materials and many unknown parameters in the equations of damper force curve, it is time-consuming for obtaining the force curves by iterations, and is not applicable for further observations on the damper properties. Hence, a simplified solution is deduced according to the simplified bi-linear model of stress curve (in logarithm coordinates) as well as the mass conservation theory of fluid mechanics; several comparisons between the exact solution and simplified solution are made, and the results show only slightly difference between such solutions. Nevertheless, the numerical derivations are fail to predict the force behaviors of the full-scale damper performance tests, which are conducted with two identical dampers filled with nanofluids PPG3000-R972-10% and PPG1000-R972-10% respectively. The major reason is supposed to be the measurement errors caused from the rheology test. Therefore, the fluid stress curves of these two types of nanofluids are modified corresponding to the results of performance tests.In the last part, several properties of nanofluid dampers are discovered by transforming the simplified solution into the combination of two continuous curves with typical forms of viscous dampers, ; for example, the exponents of the force equations are directly equal to the exponents of the simplified fluid bi-linear stress curve and independent to the damper dimensions. On the other hand, the critical velocity, which is corresponding to the intersection point of the two force curves, is independent to the length of piston head but could be enlarged by reducing the radius of piston head and increasing the width of annular gap.Furthermore, the same nanofluid dampers, used in the full-scale damper performance tests, are adopted to verify that the nanofluid dampers meet the requirements listed in the European Standard (EN15129) for the shock-transmission units (STU). Through inputting the recorded data from a practical bridge experiment, which is conducted by driving trucks moving at constant velocities, the energy dissipated by nanofluid dampers is merely 2% to 11% of conventional dampers. Although no former study confirms that the accumulative damping energy will directly affect the durability of one damper (or the seal system), the less energy implies that the seal system will receive smaller pressure and wear.